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Dyer ad nek Pratougcersy aly Fees fire AV ER OEY No wey sie dah by iets essere Fea Pisroide dee aed Gates ; ] evs bidwi tyes DivipereAgobva ney EA OG pays La anal re ars RST UT ese A irenine poh ged HPPA Db bey KE DD Db gut Steal) Pa) Un pane bioR eta) ie ar HE ns eee Eg DLE Goh D RH pte dot OP Te HRS BP tt Lig gbtotyst coageaclia shy f Do vin ea, Hien etan reais d. Digs bop by etdaads beds me reba tc eal fps PN GL ibs ae aed bs be dbs ie Dither ath he Gea au Hr bee fan p ats tet deg aide deri ed Wie Gs THAD Baro FED ROMA NON pa LD Fp A id gui seo Bap hele lb pte j ae Ce a ae mh? | Vibe ds Mie pm butea tbe hai mrad ig: a < eee eo aie, es é . ‘ : exe , v yee CN CS NO asp a woe ae oS MILT new Figure 13. —- Defense communication outposts must be pro- tected from forest fires. USFS Figure 14. — A small portion of the Anchorage float plane basin. ro" a ae x : ao, ae = = - a = == 4 dee be ee es Se Se 2 > - Figure 16. — Alaskans travel on wings. \ ‘ 18 ASSESSMENT OF DAMAGES No uniformly acceptable method for assign- ing monetary values to damage by wildfire has ever been developed. Most fire control agencies use empirical formulas for estimating losses of such tangible items as timber, forage, and im- provements. But there is no reliable means of estimating losses of such intangible values as watershed, wildlife, recreation, and _ potential industry. The final evaluation also depends on several controlling factors such as severity of burn, weather and fuel conditions at the time of burn, topography, and even the time of year. The Battelle Institute states in the conclu- sion and recommendations of its report on the cooperative forest fire control problem that no statistically supportable method is now avail- able for evaluating the impact of fire on natural resources, and that further studies on the conse- quences of wildfire to watersheds, including downstream effects, should be encouraged (Swager, Fetterman, and Jenkins 1958). The annual reports of the Director of the Bureau of Land Management show assigned estimated damage from wildfire. For the years 1950-58 the average estimated dollar value of damage amounted to approximately 10 cents per acre in Alaska compared to 8.6 cents per acre for all other land protected by BLM person- nel. Three questions arise: (1) How realistic are the present damage estimates? (2) By how much would damage be reduced if the expenditure for protection were doubled or even quadrupled? (3) How much research is warranted to help bring these two figures into a proper economic relationship, bearing in mind the values at stake discussed earlier in this chapter? 19 Table 44 lists three categories of tangible damage — timber, reproduction, and forage. Since the money value of timber and reproduc- tion in Interior Alaska is now only a potential one, the value assigned to destroyed timber can also be only potential. Persons concerned with developing an assured future supply of wood and fiber know that it is necessary to protect the present crop, but without adequately devel- oped procedures they cannot prove it in actual dollars and cents. Values for immediate loss of forage can be computed within reasonable limits of accuracy. A more difficult task is estimating the impact on animals that have to graze on other ranges and the hardship on local residents when the game or reindeer that they depend upon for food move out of their area. Losses of homes, farm property, and busi- ness establishments are both tragic and costly to owners. Computation of monetary loss from such misfortunes, however, is rather simple since accepted methods of damage appraisal have been used for many years and are available for that class of property. No one knows how much employment and revenue may be lost because interested poten- tial investors tend to shy away from establishing businesses or industries in an area where a con- tinuing source of raw material cannot be reason- ably assured. This problem certainly exists or will exist in the near future for the wood fiber Research and de- velopment must aim at establishing and main- industry in Interior Alaska. taining standards of fire control commensurate with the need for industrial security. BLM — ee EI AO, Sty BLM Figure 18. — More than money was destroyed here, near Fairbanks. 20 CHAPTER 3 GEOGRAPHY AND CLIMATE From a fire control standpoint Alaska, like most western States, has some portions that are considered easy, some moderate, and some criti- cal. What makes one area easy and another criti- cal? Usually considered pertinent to this ques- tion are the following factors: (1) The geographic arrangement of the land in relation to elevations and general weather patterns, (2) climatic con- ditions, which are generally influenced by the geographic pattern, (3) weather patterns on a local and short-term basis, and (4) fuels, as in- fluenced by all the above factors. Fuels are dealt with in a separate chapter (ch. 4). The first two factors are described in rather general terms to help set the stage for more specific information that follows in the remainder of the publication. PHYSICAL GEOGRAPHY Alaska is by far the largest of the 50 States —a vast expanse of land lying north of the Pa- cific Ocean, separated from the larger land mass of Siberia to the west by Bering Strait and joined along the 141st meridian on the east to Yukon Territory, Canada. Alaska contains 586,400 square miles (375,296,000 acres); about one-third of this acreage is in the Interior Basin. Geo- graphically, Alaska is divided into seven areas — South Coast, Copper River Valley, Cook Inlet, Bristol Bay, West Central, Arctic Drainage, and the Interior Basin as drawn in figure 19. SOUTH COAST The Aleutian Islands and Southern and Southeastern Coastal Areas combine to form a 1,500-mile crescent-shaped coastline; at some points it is 120 miles in depth. At its eastern extremity this area is mountainous, cut by a great number of tidewater bays, sounds, inlets, and fiords. Huge glaciers descend the mountain passes and often flank these shoreline indenta- tions. Mountaintops are above 5,000 feet and several rise to heights of 10,000 to 15,000 feet. The precipitous slopes of the mountains from Kodiak Island eastward are mostly clothed to heights of 1,000 to 3,000 feet by dense stands of spruce, hemlock, and some cedar. The Alaska Peninsula and adjacent islands southward from Kodiak Island are devoid of forests, but are cov- ered with luxuriant growth of native grasses. 21 About half of southeastern Alaska consists of islands. Prince of Wales Island — the largest — is 140 miles long by 40 miles wide. The largest fresh-water streams in the area are the Stikine and Taku Rivers, which rise in British Columbia. COPPER RIVER VALLEY Copper River Valley is surrounded by four mountain ranges varying in height from 4,600 to 17,000 feet. The Alaska Range forms the north boundary, St. Elias the east, Chugach the south, and the Talkeetna Range the west. Copper River Valley is nearly 120 miles long and up to 50 miles wide. Icefields and glaciers are the main sources of water for the Copper River. The basin is a high plain with elevations as great as 2,500 feet above sea level. This valley is dotted with numerous lakes surrounded by stands of spruce and birch timber. Many areas within the valley are covered by dense stands of native grass and tundra species. COOK INLET Cook Inlet Division embraces most of the Kenai Peninsula, the famous Matanuska Valley, and the delta of the Susitna River. It is bordered by the Alaska Range, and the Talkeetna and Kenai Mountains. Elevation of the valley floor varies from sea level to about 2,500 feet. Vege- tation varies from rather luxuriant grasses and some spruce and hardwoods on the Kenai Penin- sula to heavy stands of spruce and some very fine birch in the central and northern portions of the Division. BRISTOL BAY Bristol Bay Division, nearly 500 miles long by 180 miles wide, drains into the Bering Sea. The Kuskokwim River is the largest river that drains this area. The coastal and valley portion is undulating to rolling; its elevation varies from sea level to nearly 2,000 feet. It is studded with hundreds of lakes and potholes. On the northwest the zone is bordered by the Kuskokwim Mountains and on the south and east by the Aleutian Range. These mountains vary from foothills to precipi- tous peaks nearly 9,000 feet high. The land is clothed with dense growths of tundra and native grass species, but island- fashion stands of spruce and birch timber are scattered over it. WEST CENTRAL West Central Division embraces an area 480 miles by 300 miles with a coastline cut by scores of bays into which several rivers and creeks flow. The large delta formed from residue carried by the Yukon and Kuskokwim Rivers, which pass through more than 350 miles of this area, contains a myriad of lakes and bogs. The topography of this large land mass generally consists of low flat muskeg bogs and undulating hills, varying in height from near sea level to 1,400 feet. of the Seward Peninsula is mountainous and has peaks rising to 3,800 feet. ARCTIC DRAINAGE However, the southern half Arctic Drainage Division comprises all of the area north of the Brooks Range Divide, the Kotzebue Sound Area, and the Kobuk and No- atak Rivers. Three-fourths of the 1,200-mile shoreline is north of the Arctic Circle. The Kotze- bue Sound Area is a low tideland delta sur- rounded by gently rolling hills. Most of the land up to 3,000 feet elevation is covered by moss, lichens, brush, and grass, but some dense stands of spruce occupy the most favorable edaphic sites. The arctic slope is a high, rolling plateau, gradually lowering to near sea level, where it is dotted by numerous lakes, muskeg bogs, and rivers. The Meade, Chipp, Colville, and Canning Rivers have their sources in the plateau area of the Endicott Mountains and flow northward into the Arctic Ocean. INTERIOR BASIN Interior Basin embraces most of the Yukon River drainage and the upper portion of the Kuskokwim Valley. The Endicott and Philip Smith Mountains, a part of the Brooks Range, delineate the northern limits of the area; between these and the Alaska Range lies the drainage basin of the great Yukon River. The Alaska Range is composed of peaks more than 10,000 feet above sea level, including North America’s highest peak, 20,300-foot Mount McKinley. Major features of the Interior Basin Division 22 are the Yukon Flats on and near the Arctic Circle and the adjacent mountains with elevations up to 6,000 feet. The Tanana River Valley, with an area of about 24,000 square miles, lies north of the Alaska Range, whose glaciers supply most of the southern tributaries of the river. The upper half of the valley is rough and broken, while the lower portion has considerable level and gently rolling country; some of it in the vicinity of Fairbanks is adapted to agriculture. The upper portion of the large Kuskokwim River Valley is dotted by lakes and lesser rivers, many of which are often bordered by timber stands to varying widths. The intervening area is covered by mosses, brush species, and native grasses. The elevation of much of the valley area varies from near sea level to only 2,300 feet. CLIMATE Climatically, Alaska is a land of dramatic contrasts. Annette, near Ketchikan, in southeast Alaska receives 97 inches of precipitation and the temperatures may fall between 1° and 86° F. But at Fort Yukon on the Arctic Circle, only 6, inches of precipitation falls and the temperature varies from —75° to 100° F. Information in this chapter is confined chiefly to summertime condi- tions within Interior Alaska. The movement of these high and low pres- (p. 4) brings different climatic conditions through the State. Variation in tem- perature, air moisture, precipitation, and the geographic distribution of these factors is im- portant to fire control, particularly during spring and summer seasons (Kincer 1941). sure regimes Watson's (1959) study of Alaska climate divides the State into four major zones (fig. 20) that are actually consolidations of the seven geo- graphic divisions outlined in figure 19: 1. Zone of dominant maritime influence. 2. Transition zone. 3. Dominant continental zone. 4. Arctic drainage zone. Isolines of figures 21 through 27 show the variation of precipitation during the spring and summer months and the normal annual total. - The reader should refer to these while studying the ensuing climatic descriptions. } | ae ait fer penne ) oan BN i Li oan fe pushes } \ } / | a an OF } | pwiaw UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1; 250000. AND OTHER OFFICIAL SOURCES 1954 oo aso ues DATUM IS MEAN SEA LEVEL LEGEND @ CLIMATOLOGICAL DATA STATION mm OPERATIONS AREA HEADQUARTERS # DISTRICT FIRE CONTROL OFFICE & GUARD STATION === PRIMARY HIGHWAY = GEOGRAPHIC DIVISIONS SOURCE: U.S. WEATHER BUREAU. CLIMATES OF THE STATES, ALASKA. NO. 60-49 Sai ath yaaa S SD St a he SPST Th Figure 19 { { UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1: 250.000. AND OTHER OFFICIAL SOURCES 1954 San hace DATUM IS MEAN SEA LEVEL — LEGEND @ CLIMATOLOGICAL DATA STATION ® OPERATIONS AREA HEADQUARTERS # DISTRICT FIRE CONTROL OFFICE % GUARD STATION === PRIMARY HIGHWAY ee ON ie Lee ew ee = GEOGRAPHIC DIVISIONS ak eo @t FORT YU 1S) oat eS es { SOURCE: U.S. WEATHER BUREAU. : Sees CLIMATES OF THE STATES, ae : BS Ne ALASKA. NO. 60- 49 we O ® Dees. ES @a/a Caw 5 ,. NA a ea @# HOMER 2, oot Nentye er . ER AS ” Bg SAC Nites Figure 19 UNITED STATES DEPARTMENT OF. THE INTERIOR } GEOLOGICAL SURVEY } ALASKA | MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1.250 000, AND OTHER OFFICIAL SOURCES. DATUM IS MEAN SEA LEVEL _ LEGEND CLIMATOLOGICAL DATA STATION We OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION === PRIMARY HIGHWAY —— CLIMATOLOGICAL ZONES SOURCE U.S. WEATHER BUREAU. CLIMATES OF THE STATES, ALASKA. NO. 60-49 Figure 20 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAI CE TOPOGRAPHIC SERIES. SCALE 1: 250 000. AND OTHER OFFICIAL SOURCES 1954 DATUM. IS MEAW SEA LEVEL — LEGEND @ CLIMATOLOGICAL DATA STATION ™ = =OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE ®% GUARD STATION he 7 ae BY re foe == PRIMARY HIGHWAY eRe ae Tigo MSS oe Se ——CLIMATOLOGICAL ZONES Pease noe) = a ae 5 et Wane OR rg. eee | SOURCE’ U.S. WEATHER BUREAU. yp sp aie CE ee 7 ae eee! CLIMATES OF THE STATES, Pict § eR sale : sy : \ ad ALASKA, NO. 60-49 Lea ee & @LA E MINCHUMINA (oy & PALME @* ANCHORAGE EE? sagpre au me Hey Uf 4 FEM xe. Gy On wid UA UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1: 250.000, AND OTHER OFFICIAL SOURCES nvlavit \ DATUM IS MEAN SEA LEVEL LEGEND | : @ CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS ae DISTRICT FIRE CONTROL OFFICE | (och Oa GUARD STATION | ie == PRIMARY HIGHWAY ——— NORMAL PRECIPITATION PATTERN, APRIL se SOURCE: U.S. WEATHER BUREAU. Velie CLIMATOLOGICAL DATA, | : Kote ALASKA, 1958. rN = an \ as vay a A “Prvew 3 outa at FASO oa * ARR SO eo a | Figure 21 i i ; \ : UNITED STATES L LS i ‘ ; : : es DEPARTMENT OF. THE INTERIOR BAU UE ORI \ : — . GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1; 250.000, AND OTHER OFFICIAL SOURCES 1954 100. 150 MILES 150 KILOMETERS DATUM IS MEAN SEA LEVEL LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION pipe ‘ === PRIMARY HIGHWAY i Af ¢ Ste ‘ . Sees oe so Sot Bo ; —— NORMAL PRECIPITATION PATTERN, Peas a < APRIL PRS R SOURCE: U.S. WEATHER BUREAU. CLIMATOLOGICAL DATA, ALASKA, 1958. aoe ppl se 4 GIS 1@ BIG DELTA ha ee BUFFALO CENTER eto 16 LAS Shr Soh ey MING! nae Noo Maa yi : : Cire, eae TANACRO na ok GUE Figure 21 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1; 250000. AND OTHER OFFICIAL SOURCES 1954 100 _1gp Mites 150 KILOMETERS DATUM IS MEAN SEA LEVEL LEGEND @ CLIMATOLOGICAL DATA STATION mm OPERATIONS AREA HEADQUARTERS #& DISTRICT FIRE CONTROL OFFICE ® GUARD STATION s=== PRIMARY HIGHWAY MAY SOURCE: U.S WEATHER BUREAU. CLIMATOLOGICAL DATA, ALASKA, 1958 Levant Rive wee Shee, Figure 22 | | | WA f al “FORT YUKON | on ~~ Sf we yy CENTRAL $2 er ary " a? ya FAIRBANKS [yf ae A ye Afi hts cat @® BIG DELTA Wa BUFFALO CENTER PR AL, CHUMINA 4 fs ANACROSS ers S1y 3 pyvammyrie Pal” : MMIT RR SEED OY GN RATH ‘i Pet Soehes ie ae. , at be i 4 ALLEN FR i Pelee Vv eax SPAA UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILEO FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1: 250.000, AND OTHER OFFICIAL- SOURCES 1954 eee 150 KILOMETERS, DATUM IS MEAN SEA LEVEL — LEGEND CLIMATOLOGICAL DATA: STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION === PRIMARY HIGHWAY MAY SOURCE: U.S WEATHER BUREAU. CLIMATOLOGICAL DATA, ALASKA, /958. Ve, } BS See Barn en we “ Pons PH os Me Figure 22 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1, 250.000. AND OTHER OFFICIAL SOURCES 1954 DATUM IS MEAN SEA LEVEL LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS a DISTRICT FIRE CONTROL OFFICE | Peay 2 ; GUARD. STATION | be aa == PRIMARY HIGHWAY | \ — NORMAL PRECIPITATION PATTERN, | | Veen 4 JUNE emer, SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ‘ : ALASKA, 1958 pret % ca Figure 23 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE |; 250.000, AND OTHER OFFICIAL SOURCES 100 __150 MILES 150 KILOMETERS, —— Seu Aula DATUM IS MEAN SEA LEVEL “| LEGEND CLIMATOLOGICAL DATA STATION ] OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD. STATION === PRIMARY HIGHWAY EATER a RT YUKON 213 met SNe ty SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958. ib beddte LAKE ~MINCHUM N Wi OTe, Figure 23 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1; 250.000. AND OTHER OFFICIAL SOURCES 1954 150 MILES, 150 KILOMETERS DATUM IS MEAN SEA LEVEL LEGEND @ CLIMATOLOGICAL DATA STATION % OPERATIONS AREA HEADQUARTERS #& DISTRICT FIRE CONTROL OFFICE % GUARD STATION === PRIMARY HIGHWAY —— NORMAL PRECIPITATION PATTERN, JULY SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958 N Fe ARAL SOE cero : aN Kae DPSEMRTN ram ane ie Figure 24 Pra, am if } yf wb ah yy 7 Ty wee nl Blah alot te ly +9 ; Bip edb a UNALAKL EET fist LOFT EW hie Y spy Las W) ! bigee eee ny TNCH MMI ts ss yt AHEL LKANS fi. HOMER 46 power re ipanin? Na pureosn ant UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1; 250000, AND OTHER OFFICIAL SOURCES 1954 180 MILES 150 KILOMETERS. DATUM IS MEAN SEA LEWEL LEGEND @ CLIMATOLOGICAL. DATA STATION m OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE 2% GUARD STATION m= PRIMARY HIGHWAY ——— NORMAL PRECIPITATION PATTERN, JULY SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958 Figure 24 Jeasenn — LEGEND @ CLIMATOLOGICAL DATA STATION m OPERATIONS AREA HEADQUARTERS # DISTRICT FIRE CONTROL OFFICE & GUARD STATION seme PRIMARY HIGHWAY UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1: 250000, AND OTHER OFFICIAL SOURCES 150 MILES, = 50 KILOMETERS DATUM IS MEAN SEA LEVEL —— NORMAL PRECIPITATION PATTERN, AUGUST. SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958 f is [ecto Landing (gs e. ees, ean Ia BOR, s Figure 25 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1.250 0C0. AND OTHER OFFICIAL SOURCES 1954 ‘so autes $0 KILOMETERS savik Awan DATUM IS MEAN SEA LEVEL LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION meme PRIMARY HIGHWAY a) a ROE see? a a Xi 4 S \ i =——— NORMAL PRECIPITATION PATTERN, @ & FORT YUKON tS Ow eee we AUGUST. +e SF a , SOURCE® U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958 h, Figure 25 ae ze icra = \ Iv \ sane 007" | A ‘ \ awa eee Jeno \ \. \ ~ pai ( + \ aS v 4 NF e i a y © & 4, x a E Ly. 4 6 bg a UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECUNNAISSANCE TOPOGRAPHIC SERIES, SCALE 1; 250 000. AND OTHER OFFICIAL SOURCES DATUM IS MEAN SEA LEVEL _— LEGEND @ CLIMATOLOGICAL DATA STATION ™@ OPERATIONS AREA HEADQUARTERS 4& DISTRICT FIRE CONTROL OFFICE — % GUARD STATION == PRIMARY HIGHWAY —— NORMAL PRECIPITATION PATTERN, APRIL. THROUGH AUGUST. SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958. fe AB SH PIS Figure 26 NV i ge f TSO. Ha ¢ = A aid SD ip Puy ¥ZH TANANA bt if PL 2 Net Pie ge fey Ay fa FAIRBANKS Ree A punk EAs ya to @ LAKE MINC Psy AA RG eh « ab UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECUNNAISSANCE TOPOGRAPHIC SERIES, SCALE |: 250.000, ANO OTHER OFFICIAL SOURCES 1954 150 MILES St 150 KILOMETERS = DATUM IS MEAN SEA LEVEL LEGEND ® CLIMATOLOGICAL DATA STATION ™ OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE & GUARD STATION mmm== PRIMARY HIGHWAY =——— NORMAL PRECIPITATION PATTERN, APRIL THROUGH AUGUST. SOURCE: U.S. WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958 7 goo, i ip rp RN cen" ae ie Figure 26 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ay ALASKA COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1; 250 000. AND OTHER OFFICIAL SOURCES , wh \ Ania" \ DATUM IS MEAN SEA LEVEL LEGEND [ @ CLIMATOLOGICAL DATA STATION ® OPERATIONS AREA HEADQUARTERS #& DISTRICT FIRE CONTROL OFFICE & GUARD STATION == PRIMARY HIGHWAY —— NORMAL PRECIPITATION PATTERN, ANNUAL SOURCE: U.S, WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958. Le E. vai Ce See . Me : A ox eR SiO Fei Soe | Figure 27 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1, 250.000, AND OTHER OFFICIAL SOURCES . 1954 % 150 MILES = == 0 DATUM IS MEAN SEA LEVEL LEGEND @ CLIMATOLOGICAL DATA STATION ® OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE hk GUARD STATION Pha Gh teen mane : eae == PRIMARY HIGHWAY Piae en gies | aS, ‘ /goars —— NORMAL PRECIPITATION PATTERN, ANNUAL. SOURCE: U.S, WEATHER BUREAU, CLIMATOLOGICAL DATA, ALASKA, 1958. ye BIG DELTA py By LO &GLENNALLEN “Fp Eek bg RAK @ GULKAN Figure 27 ZONE OF DOMINANT MARITIME INFLUENCE Ruggedness of the topography in this zone markedly affects local climatic conditions. It produces great differences in temperature and precipitation in local areas that are not very far apart. Climatic conditions at individual locations in this zone are characterized by small variations in temperature, high humidities, high fog fre- quency, considerable cloudiness, and abundant precipitation. Extremes of temperature are quite localized and usually of short duration. The warmest tem- peratures usually come in late July or in August. Throughout the Maritime Zone only about one station in 15 reaches or exceeds 90° F. The mean temperature during these months is near the mid- fifties. Temperature changes between seasons are gradual; the length of the growing season varies considerably from one year to another. The average freeze-free period varies from 120 days in the north to 150 days in the south. Freeze- free periods within any given locality vary within wide limits. The overflow of cold air from intense high pressure cells over the mainland interior produces downslope winds that attain destructively high speeds at times. Because of its exposure to the open sea, the entire Maritime Zone is vulnerable to strong winds associated with intense cyclonic circulations that frequent these northern ocean areas. Throughout the coastal area the rugged terrain produces extremely localized wind con- ditions. Precipitation ranges from about 25 inches annually in the northwest portion to 221 inches in the southeast. The steep terrain, rising out of the sea, creates topographic inducement for the high rates of precipitation along the northern Gulf Coast. Visibility is usually low because of cloudy and foggy weather. Fog, usually the advective type, occurs frequently during the summer over the Aleutians and often drifts eastward to blan- ket the western Gulf Coast. 23 TRANSITION ZONE The change from a maritime to a semicon- tinental climate characterizes the Transition Zone. This change is rather abrupt along the boundary between the South Coast and Copper River Divi- sions because of the sharp ridge of mountains along this boundary. The Bristol Bay and West Central portions have a gradual climatic transi- tion since moisture-laden air moving toward the interior meets no formidable mountain barriers. Typical maritime features become less prominent farther inland: temperature varies more mark- edly; humidities are lower; cloudiness declines; and precipitation totals recede. The Copper River Basin has extremely cold winters, but maximum temperatures reach 90° to 95° F. in summer. This climatic feature of the Copper River Basin indicates that its weather pat- tern approaches that of the Continental Zone. In areas more directly affected by maritime in- fluences, extreme hiahs range around the mid- eighties. The average freeze-free season varies from 52 to 132 days. The 169-day freeze-free period recorded at Homer one year was exceptional. Precipitation in the Transition Zone markedly decreases from the high averages in the Mari- time Zone. A drastic reduction in precipitation in the Copper River Valley and land westward to the upper Matanuska Valley is caused by the configuration of the sheltering Chugach Range. Thunderstorms are common in the Copper River area during the summer. Precipitation generally ranges from 10 to about 30 inches. A few local areas receive heavy precipitation (75 to 80 inches) because south- easterly winds resulting from low pressure cen- tered near the Alaska Peninsula are hardly af- fected by sheltering terrain. In contrast, the Kenai Range shelters the western Kenai Penin- sula from the southeasterly winds, and the total precipitation there is comparable to that in Mata- nuska Valley (15 inches at Palmer). On the more exposed southern tip, annual totals average 25 to 40 inches. The Aleutian low pressure cell is usually weak in early spring; hence, April has the least precipitation of any month of the year at prac- tically all points over the zone except the Copper River portion. Precipitation increases markedly over the mainland beginning in late June. The low tends to move northward across the Bering Sea and brings a rather persistent southwesterly flow into the Interior. During August cloudy, rainy weather predominates and the _ interior points of the West Central portion receive meas- urable precipitation on 4 days out of 5. The westward drift of the low becomes pronounced in late November or early December, and pre- cipitation declines rather sharply over most of the Transition Zone. The permafrost area varies with summer warmth and winter cold, but it extends south- ward well into the northern portions of this zone. It is present from the northern slopes of the Wrangell Mountains through the Glennallen and Holy Cross areas, along the inland borders of Cook Inlet, Bristol Bay, and West Central por- tions. The amount of continuity is shown in figure 28. Over the Copper River and Cook Inlet por- tions, winds are usually light, chiefly because of the sheltering by nearby mountain ridges. Strong, localized winds develop in some areas as the result of downslope drainage. Most frequent ob- servations of these winds have been in the lower Matanuska and Knik River Valleys, mostly dur- ing the winter. These strong winds may persist for days when even slightly reinforced by flow patterns usually associated with low pressure systems centered near Kodiak Island or the Gulf of Alaska. Certain areas of the Bristol Bay and West Central portions are relatively unsheltered and are frequented by strong winds that often extend their effectiveness well into the interior. DOMINANT CONTINENTAL ZONE Two major factors contribute to the typical continental climate: (1) the area's remoteness from the open sea, and (2) mountain barriers that prevent inland movement of marine air. The Interior Basin experiences great sea- sonal temperature extremes: Maximum tempera- 24 tures reach or exceed 90° F. almost every sum- mer. Fort Yukon and Eagle have daily maximum readings averaging 70° to 75° F. during July and August. Prolonged daylight in early June through late July contributes strongly in main- taining high temperatures. above the horizon continuously for about 1 month at Fort Yukon beginning about June 5. During this season, the average diurnal tempera- ture change is about 30° F.; however, ranges of only 10 degrees have been recorded. The sun remains The Interior Basin has recorded the highest and lowest readings for all of Alaska. Tempera- tures at Fort Yukon have ranged from a high of 100° F. to a low of —75° F. Combined with its counterpart in Canada's Northwest Territory, the Interior Basin records provide a classic example of the northern hemisphere continental climate. Terminal dates of the freeze-free season (mid-May to late August) can be depended on as a result of the sharp rise in spring tempera- tures and an equally sharp decline in the fall. Permafrost underlies the soil in most of the Interior Basin in spite of the warm summertime temperatures. Ground temperatures remain rather cool except for a shallow surface layer. Gradual thawing of the permafrost during the summer allows ice-cold water to permeate the soil layers immediately above it. The cooling effect, when extended to the soil mantle utilized in vegetal growth, slows seasonal production of vegetation. The Interior Basin is almost surrounded by a high ridge of mountains; their sheltering effect is @ primary cause for the light precipitation (6 to 14 inches) in this area. Most of it falls in June and July, but occasionally some occurs in Aug- ust. Average monthly rainfall during these months totals close to 2 inches — slightly less than averages for the growing season over the central and western parts of the Dakotas. Total summer precipitation may vary widely within relatively short distances chiefly because shower- type precipitation predominates. In local areas thunderstorms may occur on several consecutive days. ger OO awied™ UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1; 250 000. AND OTHER OFFICIAL SOURCES 1954 DATUM IS MEAN SEA LEVEL LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION === PRIMARY HIGHWAY seers PERMAFROST DISTRIBUTION SOURCE: HOPKINS ET AL (1/955) Figure 28 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1: 250 000. AND OTHER OFFICIAL SOURCES 1954 0 = Oo 50 100 sso mies 50 100 150 KILOMETERS — <== SN Loa DATUM IS MEAN SEA LEVEL _ LEGEND @ CLIMATOLOGICAL DATA STATION m = =OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE &% GUARD STATION s=== PRIMARY HIGHWAY AUD ioe ON Det Lien Re xy ® -BETTLES a sere PERMAFROST DISTRIBUTION SOURCE’ HOPKINS ET AL (1955) J 4 Na Apa seal Se BIG DELTA Be we id 2 PA RNACROSS - cLERINALLEN i Ae b : oe Yi Cm Mp Aaa | sos RE rd Ny Bie Sea OE TRA a ® ILIAMNA p } hi Ske sae a Ra Si Ww ay ce: Figure 28 Si tee a ree On = — SS = — = Te i = = = Se hn ee ae tems air tee —— — OOO ee ——————— ARCTIC ZONE Climatic conditions of the Arctic Zone are Unique and contrast sharply with conditions in other zones. The effectiveness of the Brooks Range in influencing the climate of the land area to the north has not been definitely established, al- though the Range is a topographic barrier. Variations in temperature here are confined to narrower limits than in the Interior Basin. Extremely low temperatures in this zone range between —45° and —60° F. Seldom do maxi- mum temperatures reach 80°F. Even during the prolonged period of continual daylight, the sun's rays reach the earth's surface at such low angles that they cause little surface warming. Mean hourly windspeeds in summer aver- age from 11 to 15 miles per hour. Maximum summertime windspeed has reached 52 miles per hour at Point Barrow. Average annual precipitation for this zone is from 5 to 10 inches, although 16 inches occurs near Cape Lisburne. Annual snowfall totals average about 50 inches east of Cape Lisburne and from the Arctic Coast to the Brooks Range. Kotzebue experiences the warmest average tem- peratures and consequently receives a smaller ratio of snowfall to total precipitation than the remaining portion of the zone. The low moisture-carrying capacity of the colder air that prevails over the area accounts for this zone's having such light precipitation. The average freeze-free period contrasts with that in other zones; it ranges from 65 days in the Shungnak area to just short of 90 days at Kotzebue. The coastal area north of the Brooks Range has minimum readings averaging near or below freezing for all months of the year; vege- tal growth is limited to those species that can endure the vicissitudes of this rigorous climate. WEATHER FACTORS THAT AFFECT FIRE BEHAVIOR AND CONTROL Weather conditions are highly important to ignition and spread of wildfire. The amount and frequency of precipitation, air temperature, air moisture, and air movement combine to produce 29 the dryness and consequently the flammability of fuels. Other atmospheric conditions also strongly influence behavior of a going fire. For example, a thunderstorm not only starts light- ning fires, but its presence may often cause er- ratic winds that blow the fire out of control. To interpret the normal weather patterns at various places and at different times of day, month, and year, weather records from 18 sta- tions have been analyzed for the period 1950- 58.4 Observations taken from these 18 stations sample the climates experienced in their respec- tive climatic zones (fig. 20). The individual sta- tions are widely separated and only represent the heterogeneity of climes experienced in the State. The recorded data show the normal con- ditions that can be expected; however, local or temporary weather situations are often abnor- mally worse. PRECIPITATION Precipitation varies widely throughout the State, but generally decreases from south to north (figs. 26 and 27). Successive east-west mountain ranges prevent moist maritime air from reaching interior regions. Great variation in summer rainfall is indi- cated by the records at representative weather stations in the Interior Basin, West Central, and Cook Inlet climatic divisions. (See table 1 and figs. 21 through 25). The combination of time of year with amount of precipitation that falls then is an im- portant factor influencing fire behavior. The length of time between summer rains has an important bearing on the amount of growth and the degree of curing in the herbaceous species; duration of these periods likewise affects the moisture content of dead material. Long periods of dry weather hasten the curing date of herba- ceous vegetation, and thus extend the period of high flammability. Table 2 indicates distribution of rainfall among the 4 summer months and the ratio of this season's precipitation to the annual total. 4Summary of the analyses appears in the appendix and is highlighted in this chapter. Table 1. — Variation in summer precipitation Weather station May Normal Max. Min. Anchorage O51 2:00! 70:02 (Cook Inlet) Bethel 89 2.50 .02 (West Central) Fairbanks Agee 275 .O7 (Interior Basin) McGrath 94 1.98 .34 (Interior Basin) Growing conditions early in the season de- pend upon fall and winter moisture because too little precipitation falls early enough in the spring to promote plant growth. A deficiency of winter precipitation or early loss of snowpack may indi- cate the possibility of early periods of high flammability; in addition, this set of circum- stances can cause deeper than normal drying of ground fuels which so often means a greater resistance to control of fires. For most reporting stations, the monthly precipita- tion increases during the summer. Less than 20 percent of the normal annual precipitation falls between April and June. Only a few interior stations report more than 35 percent of their than usual Month June July Normal Max. Min. Normal Max. Min. 0.89 2.94 0.03 1255583) 2 5 OLY, 1.20 2.48 .30 DiI2DOWS395 49 IES/eeeSra2 P| 1hO2Qe FAl24' .40 2.06 4.36 42 DSO NTS 76 annual precipitation during the period generally considered the growing season. The amount of moisture that falls in any single storm period is important to fire control. The frequency of moisture occurrence affects the flammability of the vegetative materials and the rate of buildup of fire season severity. Rainfall intensities greater than 0.25 inch in any one day occur but seldom (table 3). Virtually no precipi- tation falls on three-fourths of the days in May. At very few stations did more than 0.26 inch of precipitation occur on one or more days during May. During April, the weather is even drier. In May and June both frequency and intensity of rainfall gradually increase. Table 2.—Percent of normal annual precipitation, April through July (Av. 1950-58) Weather Month station April May June Anchorage 2.8 3.6 6.2 Bethel 3.0 4.9 6.5 Fairbanks 2.4 6.2 les Fort Yukon 2.6 4.9 10.9 Galena as: 4.3 11.6 McGrath 2.6 4.9 10.8 Northway 3.1 6.3 17.6 26 Seasonal Tayi ge reco ae Inches 10.9 23.5 14.27 12.6 27.0 18.17 16.1 36.2 11.92 14.8 Sore 6.52 18.6 35.8 14.55 2 30.4 19.13 25.6 52.6 11.34 | | || | t } i] Table 3.—Rainfall intensity classes by number of days per month (Av. 1950-58) Weather Month station May June July Normal 0.0- 0.01- Normal 0.0- 0.01- Normal 0.0- 0.01- ppt. trace 0.25 0.26+ ppt. trace 0.25 0.26-+ ppt. trace 0.25 0.26+ Anchorage 0.51 26.6 4.0 0.3 0.89 21.3 7.9 0.8 1.55 18.9 9.4 2.7 Bethel 89 18.6 9.6 8 1.20 18.1 10.8 11 2.29 15.5 13.0 2.4 Fairbanks 74 25.2 5.3 5 87 207 7.8 1.5 1.92 16.3 8.6 ya) Fort Yukon 32 28.0 2.8 2 aA 23.8 5.7 5 96 25.3 5.4 3 Galena .63 24.5 6.1 4 1.69 21.4 Ti. 9 2.69 19.4 9.4 22 McGrath 94 23.8 6.5 7 2.06 19.6 9.1 1.3 2.32 17.8 9.8 3.4 Northway 72 23.0 6.9 1] 2.00 19.5 8.7 1.8 2.89 18.4 10.6 2.0 Fort Yukon receives slightly less than 2 radiation and the surrounding air mass. Both inches of rainfall during the May-July period; exposure and arrangement of fuel particles bear 77 days are rain free, and more than one-fourth on the actual temperature the fuel attains. Air inch will fall on only 1 day during the 3 months. temperature also affects the rate of moisture loss TEMPERATURE following a period of wetting by rain or dew. Observation and knowledge of air tempera- Temperatures are higher in the Interior Basin ture are important in studying fire behavior. than in any other zone. Nowhere do they stay Their main value lies in the relation between above 80° F. for extended periods (table 4), but temperature and its effects on equilibrium mois- the sustained level over a period of 18 hours ture content and on ambient air stability condi- decidedly affects fuel moisture and fuel tempera- tions. Fuel temperature is affected by solar ture. Table 4.—Average daily air temperature classes (degrees F.) by number of days in each temperature class per month (Av. 1950-58) Weather Month station June July 30-39 40-49 50-59 60-69 70-79 80-89 30-39 40-49 50-59 60-69 70-79 80-89 Anchorage 0.1 572 15:9 TAS) 1.2 0.1 0) ies 14.9 L221 2.6 0.1 Bethel 4) 9.8 12.4 5.8 ileal 0 ) 4.7 16.8 7.6 1.8 mi! Fairbanks Pp) 2.3 8.9 les) 6.1 12 0) 126 9.0 11.6 720 1.8 Fort Yukon 3 3.0 8.6 11.4 6.3 4 2 1.4 Zl 123 8.4 1.6 Galena 2 3.2 11.4 10.6 4.1 5 0 1.4 11.9 11.3 5.4 1.0 McGrath a5 4.3 1L.3 929. 3.5 a5} 7] 2.8 1320 9.8 4.2 Tal Northway ES 5.2 10.5 10.2 335 23 al 322 10.9 10.8 5.3 of Afternoon temperature affects the plans for bility. More days have higher afternoon tem- control of fires. As the long day progresses, fuel moistures reach or approach equilibrium moisture content. This in turn increases flamma- peratures at Fairbanks than at Anchorage (table 5). This fact may be directly related to the greater fire problem in the Fairbanks area. Table 5.—3:00 p.m. temperature classes (degrees F.) by number of days per month (Av. 1950-58) Weather station June 30-49 50-69 Anchorage 1.0 257. Fairbanks 0 M6 PERMAFROST Permafrost consists of organic and soil ma- terial that remains frozen year round. Regional climatic differences result in variation of perma- frost thickness from more than 1,000 feet in northern Alaska to permafrost-free terrain in southen Alaska (fig. 28). Precipitation (through ground water), temperature, and insulation ma- terial affect the presence and depth of perma- frost. Permafrost, in return, somewhat influences local temperature and considerably influences the supply of usable ground water. Because of their active water movement, streams generally are underlain by deeper and wider unfrozen areas than are lakes; coarse, permeable sand or gravel is more likely to be free of permafrost than is impermeable silt. Abundant unfrozen zones at shallow depth can be expected in mountainous areas, especially on south slopes. The most favorable sites for for- mation or preservation of permafrost in moun- tain areas are on north slopes and beneath poor- ly drained surfaces on broad interfluves and valley bottoms (Hopkins, et al. 1955). Table 33 shows the time of season by which the ground is thawed to various depths. Permafrost affects vegetation in several ways that bear on fire behavior and conse- quences. The cold soil above the permafrost layer inhibits growth and delays the ‘‘greening- up’ of plants in the spring to the extent that much dry material is available for burning early in the fire season. Roots tend to grow laterally and above the frozen layer. When fire passes through a stand of timber and consumes the organic mantle, tree roots have nothing left to cling to; thereafter, even light winds can blow down large areas of trees that otherwise would have survived the fire. 28 Month July 70-89 30-49 50-69 70-89 3:3 0 24.7 6.3 1389 0) 15.0 16.0 The presence of permafrost often misleads firefighters. Frozen organic matter thaws and dries out when a fireline trench exposes it to open air; this permits a smoldering fire to escape across the once safe zone. RELATIVE HUMIDITY Air moisture is generally thought of in terms of relative humidity. In Interior Alaska, humidi- ties in May and June are lower than in July, and considerably lower than in August (tables 6 and 25). This situation is the reverse of what is usual in most of the western United States. Air moisture affects burning conditions mainly by varying the fuel moisture content. Most fine fuels are sensitive to changes in air moisture and follow the humidity pattern rather closely. In heavier fuels, moisture content changes more slowly since a much smaller per- centage of the total volume is exposed for rapid transfer of moisture. LENGTH OF DAYLIGHT Both air and fuels receive heat by solar radiation. The prolonged hours of daylight and sunshine contribute to maintaining fairly high temperatures. Lengthening or shortening of day- light at a given latitude follows the change in the meridian angle of the sun. Surface tempera- tures are higher in the summer than in the winter not only because the sun shines longer, but be- cause it shines more directly, and therefore, more intensely on the earth's surface. This potential worsening of fire-weather conditions is some- what balanced by the fact that the amount of radiant energy received on any surface area de- creases ads we move from tropical to northern latitudes because of the lowering angle of inci- dence of solar radiation. Table 6.—3:00 p.m. relative humidity classes (in percent) by number of days per month (Av. 1950-58) Weather station May 30- <30 49 50+ Anchorage Tal? 36:9) 13:0 Bethel ae -O100 24e1 Fairbanks 6:7 17.6 6.6 Fort Yukon led) “16:95 258 Galena 3:3) 13.9 71318 McGrath ZO V6.9. 175 Northway 52 11520; S058 Table 7 compares the number of hours of daylight for stations at three latitudes: Fort Yukon (lat. 66°35'N.), Anchorage (lat. 61°10'N.), and Missoula, Montana (lat. 46°55'N.). Table 7.—Duration of daylight Location Date Fort Yukon Anchorage Missoula Hrs. Min. Hrs. Min. Hrs. Min. May 1 17 30 16 i] 14 25 1] 18 52 17 06 14 53 21 20 22 17 57 15 18 June 1 DD A 18° Ag la "738 11 24 00 19 13 18 _ 50 2) 24.00 19 - 25 1a 7 53 July 1 24-00 1 is VS! eo) 1] 22 18 18 47 15 38 21 207)" ".311 18. = .06 15>. 19 The length of day or duration of possible sunshine is much greater at higher latitudes — a maximum of 5 hours greater at Fort Yukon than at Missoula, Montana. Missoula, however, re- ceives more intense heating because the sun's rays are more nearly perpendicular to the earth's surface when the sun is at its zenith. This in turn often dries out fuels more than does the longer period of lower maximum temperatures farther north. Month June July 30- 30- <30 49 50+ <30 49 50+ 0.6 10.0 19.4 0.2 62 24.6 % 4 60 23.6 0) 44 26.6 521 16:0. 8.9 3.5 12:3. “15.2 ho 187° 10:3 Zo Nom 147 3:2, 12:9 13.8 Ie 2:3 Aco 29 P1338. 13:3 1.0 11.1 18.9 52 15.2 Wee Dez Noel “Se WIND Wind influences the behavior of a fire. 29 High windspeed may cause a fire to jump bar- riers and travel in the crowns of trees, or to spot ahead of the main fire front. Wind combined with topography can cause erratic and violent fire behavior. As should be expected, afternoon winds usually are stronger than morning winds. Weath- er records indicate that Bethel is windier than most places, as the 0 to 7 miles-per-hour speed appears on very few days, but the 8 to 12 and 13 to 18 miles-per-hour range is high for morn- ing readings and at least average for afternoon readings. Fort Yukon follows the same general trend. In May, many stations record the 13 to 18 miles-per-hour range on more days than in June or July (table 8); this indicates that winds in- fluence fire behavior more in May than in other months. Many factors influence the direction of air- flow at any specific place. Geographic location determines whether maritime or continental air- flow affects a given area. Topography can cur- tail, accentuate, or change the surface direction of a prevailing wind. Winds of unusually high velocity that blow out of mountain canyons are generally associated with glaciers lying in these Table 8.—9:00 a.m. and 3:00 p.m. wind velocity classes (in miles per hour) by number of days per month (Av. 1950-58) Wind velocity classes, miles per hour Weather 0-7 8-12 13-18 19-24 2 Dict station 9 AM 3 PM 9AM 3PM 9AM 3PM 9AM 3PM 9AM 3PM May Anchorage 19.2 7.0 8.1 13.6 3.1 Tit 0.6 1.6 0.1 0.1 Bethel 9.5 4.5 12.0 1322 7.8 10.8 1.6 2.3 Hl] 2. Fairbanks 20.3 13.9 7.1 10.0 3.3 6.1 3 9 0 Al Ft. Yukon 9.8 7.8 eZ, 13.4 7.9 8.1 1.6 1.3 0 4 Galena 13.4 10.5 Hii 11.4 5.8 73 7, 1.6 0 2. McGrath 20.0 1351 9.2 12.9 1.8 4.6 0 2 0 2 Northway 15.4 11.1 11.8 12.3 317 7.2 1 4 0 0 June Anchorage 20.3 11.6 8.0 12.4 1.6 4.6 i 1.4 0 0 Bethel 8.1 7.2 14.5 13.4 6.6 8.6 7, 8 al 0 Fairbanks 19.7 13.3 6.7 10.5 BH 5.1 A 1.0 J zl Ft. Yukon 12.6 7.8 9.2 13.7 6.7 6.3 1.4 1.8 J 4 Galena 15.2 11.6 8.8 10.8 4.9 57 8 1.6 £ 3 McGrath 20.2 15.7 72 9.2 2.6 4.8 0 3 0 0 Northway 15.3 10.0 10.2 1331 3.9 6.3 6 7 0 0 July Anchorage PVes2) 15.6 Teli 11.0 123 32%, Al of 0 (0) Bethel 12.0 8.5 11.8 12.6 6.2 8.2 9 1.6 J 4) Fairbanks 23.3 15.7 6.3 10.5 123 4.6 a] 2 0 0 Ft. Yukon 14.8 9.6 9.3 12.2 5.4 6.8 1.4 2.1 él 3 Galena 18.2 14.0 6.6 O75 4.9 4.8 Ae) Ded. 4 oS) McGrath 22.8 16.8 6.3 10.8 haces ie 0 2 0 0 Northway 17.9 14.8 9.4 11.2 3.6 4.6 1 A 0 0 canyons. Taku winds, Knik winds, Delta River portant to a fire control officer. Appendix tables winds, and Summit winds are well-known ex- amples of this phenomenon. Occurrence of such winds can usually be predicted by alert fore- casters. Table 9 shows the variations between reporting stations on the frequency of changes in wind direction during the month. Of interest is the shifting from month to month of predomi- nant wind direction at the same location. These observations can be valuable in long-range fire control planning. The extremely small number of samples recorded below presents the proba- bility that even though two reporting stations have similar characteristics the intervening area may vary greatly from them. SKY CONDITIONS Sky conditions have a multiple influence on behavior and control of forest fires. Some gen- eral knowledge of what to expect in various places and at different times of the season is im- 30 29 through 32 summarize in detail the available information on the amount of cloud cover, types of weather (predominant moisture forms), visi- bility distances, and ceiling heights. The amount or extent of cloud cover and the prevalent weather type greatly affect fire be- havior and the flammability of fuels. Increased density of clouds and smoke reduces the pene- tration of sun rays, and allows only a portion of their heat concentration to reach the earth's sur- face. It also reduces the radiational heat escap- ing from the earth's surface. The combined ef- fect reduces the diurnal temperature fluctuation. Rapid changes of surface temperature resulting from intermittent shading by clouds may cause troublesome changes in wind direction and ve- locity. On one-half to two-thirds of the days during the fire season, three-fourths of the sky is covered by some type of clouds. This is equal- Table 9.—3:00 p.m. wind direction classes by number of days per month (Av. 1950-58) Weather station N NE E Anchorage ‘1.6 0.8 O7 Bethel 3.9 1.6 4.5 Fairbanks 2.6 4.4 3.9 Fort Yukon Tel 14.0 2.0 Galena 73 2.8 5.6 McGrath 4.7 Af 5.4 Northway 3.0 “7 2.6 Anchorage 2.6 0.4 0.1 Bethel 2.6 2a 2.3 Fairbanks 1s 7; 2.8 1.9 Fort Yukon 1.2 8.3 1.0 Galena 32 les 2.6 McGrath 37. De; 3.1 Northway 3.9 12 14 Anchorage! 3.3 1.0 0.2 Bethel 2.4 2a 1.7 Fairbanks! 1.3 2] 1.4 Fort Yukon 8 5a] el Galena Did 8 1.5 McGrath 2.6 1.7 1.6 Northway 3.0 1.8 2.4 TSix days’ records missing. ly true for inland and coastal areas. The amount or extent of cover gradually increases from April through August. The interior of Alaska experiences few days during May through July when the ceiling is lower than 1,000 feet. More often the ceiling height is greater than 10,000 feet. During Au- gust, when there is more rainfall, the ceiling is lower and visibility is materially reduced. Both smoke and haze affect surface weather somewhat but not nearly as much as they affect fire control activities. Reduced visibility makes fire detection more difficult. Most interior stations Wind direction SE 31 S SW W NW Calm May 9.0 PIP 6.6 4.9 Os 6.1 210) 2.1 6.6 6 4.] 5:5 3.8 2.8 lead 1.] af 4.4 1.0 0 ys 3.4 2.1 2.0 2:3 4.4 4.6 See 4.0 4 2a, 3h 4.2 9.8 1.6 June 5:13 oe2 9.0 6.3 “0:2 7.0 4.7 Df: 5.9 4 310 gE 6.3 DY, 2.0 1.6 7.0 8.3 1.6 .O De, 7.8 32 4.] oie) 6.7 5.1 3.3

tote “te $8 os Bo ecetoten SRR ROK 11 4.6 168.0 192 49 W848 “acess PROTECTED Figure 44 52 NUMBER OF FIRES. “ORS7 _ . season ACRES BURNED ° Zasiés7° ° 1950-19568 NUMBER _OF FIRES 1S \\ NY norma! KA —sdOTHER STATES. ~— OTHER STATES BLM BLM ALL AGENCIES 9 WY pee ARLA « 7 BURNED 956 EL > 6) S74 x 3 iS 2 / OTHER STATES OTHER STATES BLM BLM ALL AGENCIES Figure 45 53 AREA BURNED PER FIRE AVERAGE 1950 -/958 etatat nore” Sx Sees 962 NORMAL 1958 Figure 46 54 PERCEN TF 100 80 PERCENT OF FIRES EXCEEDING {0 ACRES AVERAGE 1950-1958 1980 & 192 NORMAL 195 WG =) WORMAL 1986 ALASKA OTHER STATES || OTHER STATES BLM BLM ALL AGENCIES Figure 47 5D FIRES BLM ALASKA — = = Wa 1950 — 1958 ] BLM OTHER FAILROAD N Fe == = ooceee LNDIARY | LUMBERING cok| ok a INC. BY SPECIFIC CAUSE AVERAGE AL lilalditaldidla 9% | Padilla AND PERCENT OF il HH ort Serhieres s HEPES YlW0da HHH@@@@@E@~PEX@YT MEC@M J came S Reefs SSS GS BS S S = 8 ees: Oe Se ooo SIININ iNiodse Figure 48 ; 56 S958 a i § ) ad N Sy aS AVERAGE 1950 nf nd Te LL S 4 Ld tO = > 2 | SLM, ALASKA S N S : 8 200 WMA. Md a Te — cotta Se NOs Figure 49 57 aq = al S S? ce o™ read a os oe < as 25 = =_ = ce Vat | ae AVERAGE 1950-1958 BLM, ALASKA | BLM, OTHER MMMM Mon HHY@H@_ CM TUM iti’ LLL hey x e2gessggsssssss Ga YSIGW/7?N Figure 50 58 The cover types in Alaska do not correspond to those in continental United States; therefore, no valid comparison of area burned can be made without modifying some terminology. In conti- nental United States rate of spread is greatest in grass fuels. A large share of the lands protected by the Bureau of Land Management in continen- tal United States is covered with grass; the next largest acreage is brushland. In Interior Alaska, grassland comprises a small percent of the total acreage; much of that is on the Kenai peninsula where lightning incidence is very low, accessibil- ity is relatively good, and fire danger seldom be- comes critical. Tundra and related fuels are not included on fire reports; fires in tundra are arbitrarily classed in the ‘‘Other'’ fuel type category. Rate of spread in this complex is as great as, if not greater than, rate of spread in the grass type. The information in figure 51 would be more re- alistic if most of the BLM Alaska acreage that is now listed in ‘Other’ fuels were placed in the Grass’ category. Seventy-four percent of the acreage burned in Interior Alaska is in forest or tundralike fuels. Eighty-eight percent of the acreage burned on other BLM protected lands is in brush and grass fuels. Forty percent of the acreage burned in Interior Alaska is in forest fuels, compared with only 7 percent on other BLM protected land. A relatively greater strength-of-attack force is needed for controlling fires in forested land. INTERIOR ALASKA, WITH SOUTHEASTERN ALASKA Up to this point all of the statistics have referred only to Interior Alaska. The differences in weather factors and fire loads between the two sections of the State make this understand- able. The brief tabulation below compares the Precipitation patterns of Interior Alaska with those of southeastern Alaska; it reveals two entirely different climatic situations. Interior Alaska has been termed ‘‘the green desert,’ but southeastern Alaska approaches a rain forest condition. Interior Normal annual Southeastern Normal annual stations precipitation stations precipitation Inches Inches Fort Yukon 6.54 Seward 68.08 Fairbanks Ua ey Juneau 90.25 Anchorage 14.27 Sitka 96.33 Bethel 18.17 Ketchikan 1593 59 Past fire records place nearly all the Alaska fire incidence and burned area within the Interior (table 14). Abundance of precipitation in the southeast accounts for the heavy stands of Sitka spruce and western hemlock timber. Much of it is overmature: this indicates relative freedom from tire. But many stands in southeastern Alaska do show evidence of fire in their age and species composition. Fire potential in the southeast increases as timber is cut. Large volumes of logging slash accumulate and expose the ground surface to insolation and rapid drying; this encourages growth of flammable grass and annual weeds. The number of people in and near the woods also increases as utilization increases. The most urgent task is to reduce the annual burned area in Interior Alaska from the present 1,119,130 acres. However, the fire potential in the southeastern section must be realized; collection of certain elements of back- ground information there will be of value to any fire research program that may ultimately be established. WITHIN INTERIOR ALASKA Lightning and Man-Caused Fires Only 24 percent of all forest fires in Alaska are lightning caused, while 76 percent of the acreage burned is due to lightning fires (fig. 52). Inadequate storm detection and difficult acces- sibility contribute to the high area-to-incidence ratio. Probably the greatest fire control chal- lenge is to reduce the acreage of lightning fires to approach the incidence percentage. Early de- tection and fast attack facilities will help bring the acreage burned into line with the number of fires. Fires on Which No Suppression Action Was Taken Several interesting but often confusing sta- tistics result from comparing the group of fires on which suppression action was taken with the group that burned completely unrestricted. Al- ready mentioned is the fact that control action cannot be taken on some fires because: (1) they are physically inaccessible; (2) they are so large when discovered that no reasonable force of men could stop them (economically inaccessible); (3) limited manpower makes it imperative to TWOUSAND ACRES AREA BURNED BY FUEL TYPE AVERAGE 1950-1958 771328 RQ Qa” BLM ALASKA BLM OTHER _ Figure 51 60 NUMBER AREA BURNED 200 900 175 Me 800 Qe 150 S 700 Wp XX 600 ~Q Q 500 ss 100 = ; D 75 SH 300 — S 50 Q NN 200 25 \ 100 NUMBER OF FIRES AND AREA BURNED BY GENERAL CAUSE Table 14.—Fire statistics, Interior versus Southeastern Alaska Lightning Man-caused Total Interior Southeast Interior Southeast Interior Southeast Number Acres Number Acres Number Acres Number Acres Number Acres Number Acres 1940-49 200 no data 1 o+ 938 nodata 292 1,649 1,138 12,411,076 293 1,649 1950-58 546 7,665,726 3 1 1,734 2,406,442 234 5,738 2,280 10,072,168 237 52739 1950-58 Av. 61 851,747 0.3 o+ 193 267 ,382 26 638 253 IANS NSO 26 638 Source: Southeast: National Forest Fire Reports, USDA, Forest Service. Interior: Annual Reports of the Director (Statistical Appendix). choose between fires when many start during a short period; and (4) under a general smoke pall some fires burn without being detected. Thirty-three percent of all lightning fires are never attacked, while only 9 percent of man- caused fires are not; however, the actual number of no-action fires per year is about the same for both general causes. This 9 percent accounts for 68 percent of the area burned by man-caused fires. A lightning fire usually is 10 times the size of a man-caused fire; but an average no-action lightning fire is only 1% times the size of a no-action man-caused fire. Many lightning fires are held down in early stages by such elements of moderate weather as clouds, high humidity, and precipitation; this is not often true for man- caused fires. Table 15 and figure 53 contain the specific information for the above discussion. Why an average no-action lightning fire is only slightly larger than an action lightning fire can lead to many conjectures. A partial explana- tion can be: (1) the more potentially dangerous fires are attacked first; (2) action not taken be- cause known barriers may restrict the fires to small size; and (3) initial attack on some action fires occurs after they have beceme too large to control; they are subsequently abandoned — hence, large acreages appear on the action fire side of the ledger that otherwise would have been charged against no-action fires. The per- centage of lightning fires upon which no action was taken has been materially reduced since 1956. Table 15.—Fires receiving suppression action Type of fire eee ae Total area burned ete ren Acres Percent Acres Ratio Lightning No action 20 303,214 15,161 Action 4] 549,574 13,404 Total 61 852,788 76 13,980 10 Man-caused No action 17 181,514 10,677 Action 176 84,828 482 Total 193 266,342 24 1,380 ] Total 254 1,119,130 4,406 Monthly Variation in Fire Frequency and Size Lightning fires——Virtually no lightning fires occur before mid-May or after the end of August. Eighty-eight percent of all lightning fires start during June and July. Class D fires are a very small percentage of the total number of lightning fires in any one month, but the number of Class E fires is consistently greater than that for any other class (fig. 54). Man-caused fires——The frequency pattern for man-caused fires deviates considerably from that of the lightning fire (fig. 54). For nearly all NUMBER OF FIRES AND ACREAGE BURNED BASED ON WHETHER SUPPRESSION ACTION WAS TAKEN AVERAGE 1950-1958 ACTION Fee=| [___] Wo ACTION NUMBER 400 : SS Se Q i < SQ . ACTION NO ACTION Figure 53 63 MONTHLY VARIATION IN SIZE CLASS OF FIRES AVERAGE” ~1950 279 5E ae Ol Ee Ba | CLASS Lael Gs 3 me PERCENT LIGHTNING oe eae ae 20 sides ia Oto ote ike 10 a SI [WE] | | (eT 3 [SEASON| 61 FIRES —orecenr MAN-CAUSED ee AVERAGE WUMBER | Pee ee 10 20 30 40 50 60 | Ee, APRIL ale Sees eerey eS] | et JUNE Y | JULY AUGUST m= _ SLPT. SN A NOV. Pee sae 192 FIRES ee ET ee ed Figure 54 of the season the greatest percentage of the fires caused by man is Class A. Fifty-seven percent of the fires occur in May and June — a month earlier than for lightning fires; land-clearing op- erations are a major reason for this early peak- load. Only a few fires occur in October and November, but a larger percentage of them reaches Class E size because the entire detection and control force has been drastically reduced by this time. Acreage burned.—The record of actual acre- age burned in each month (fig. 55) shows clearly that the small number of Class E fires during May, June, and July accounts for most of the total amount. Seventy-three percent of all acre- age burned by lightning fires occurs in June. Seventy percent of all acreage burned by man- caused fires occurs in May. Lightning fires con- tinue to burn much larger acreages in July than do man-caused fires; in fact, July lightning fires burn almost the same acreage as man-caused fires do in May. Yearly Variation in Fire Frequency and Size For the 9-season period studied, the gener- alization could be made that as the total number of fires increased, the number of Class E fires also increased, and the number of Class A fires decreased. This relationship is partly due to overloading of the fire control organization and partly due to many fires reaching such large size that no effective suppression action could be taken. The percentage of the Class B, C, and D fires does not vary greatly from year to year; the main difference in percentage is between Class A and Class E fires (fig. 56). The area- burned-per-fire record for 1957 — the worst year — and 1955 — the easiest year (fig. 46) — falls within this number-size class relationship. Distribution of Fires Fire control strategy cannot be planned properly without first knowing where and when fires are most likely to occur. Bases must be established and personnel deployed and shifted according to this knowledge. Data from the anal- ysis of fires from 1950 through 1958 were insuf- ficient to make detailed occurrence isograms for individual years or for separate size classes; however, figures 57 and 58 show the number of man-caused fires and lightning fires per million acres for this period. Most man-caused fires burn near population centers and along the primary highways connect- ing these principal cities (fig. 57). Exceptions to this general rule are such towns as Tanana and Fort Yukon. No roads go near these towns, but in Alaska they are still centers of population or distribution points. Distribution of lightning fires (fig. 58) ap- pears somewhat similar to that for man-caused fires in respect to their apparent concentrations near the larger towns and along the primary highways—particularly around Fairbanks, Tana- cross, and the connecting road. Other apparent centers of lightning fire frequency are near Kot- zebue, Galena, McGrath, and between Eagle and Central along the Canadian border. The scatter of fires was so great that this table at best could show only an approximation. If complete detection coverage were pos- sible, the lightning fire isogram might appear considerably different. Over the past many years, detection and reporting have been almost entirely by such volunteers as airplane pilots, travelers, local residents, and miners. We now know that many lightning fires occur in areas for which the isogram indicates a low frequency. Some of these fires burn large areas, and some may combine with other fires and appear as only one for reporting purposes. Others burn and die out without being reported. Many fires do not spread beyond a very small size, and their existence is never known. Better detection and better reporting methods will no doubt change the pattern of the lightning fire isogram during the next few years. More information pertaining to fire distribution according to size class and distance from headquarters appears in chapter 8. THOUSAND ACRES 600 550 RN S rs Ss bs 8 ASS) Ss Ss tS s ACREAGE BURNED BY MONTH LIGHTNING AND MAW-CAUSED HIRES AVERAGE 1950-1958 [AREA BURNED —- LIGHTNING FIRES —— —MAN-CAUSED FIRES TOTAL FIRES % Of AREA BURNED L/GHTM/NG FIRES ( MAN-CAUSED FIRES [-] 7O7AL FIRES APRIL Figure 55 66 YEARLY VARIATION IN SIZE CLASS OF FIRES AVERAGE 1950-1958 NUMBER Ss 1950 952 £8 NS! 956 1950 | ITE a a 1956 ee > > x a Maa) 100 200 300 400 500 be UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE 1, 250 000. AND OTHER OFFICIAL SOURCES DATUM IS MEAN SEA LEVEL LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION === PRIMARY HIGHWAY MAN-CAUSED FIRES PER MILLION AGRES, ALL SIZE CLASSES AVERAGE 1950-1958 Figure 57 rm" ~ * =. J os , : I + RS z . _ : aa f i us - - = i> = > i ~ UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE | 250.000, AND OTHER OFFICIAL SOURCES 1954 149 MILES —— 150 KILOMETERS DATUM IS MEAN SEA LEVEL — LEGEND 5 SU ONL gm i hs (Vane ern \ Se ® CLIMATOLOGICAL DATA STATION PAY ot GBT area 5 es z med AAV En PSAP POSH Ove m= =OPERATIONS AREA HEADQUARTERS & DISTRICT FIRE CONTROL OFFICE & GUARD STATION mm=—= PRIMARY HIGHWAY MAN-CAUSED FIRES PER MILLION ACRES, ALL SIZE CLASSES, AVERAGE /950-/958 B34 { Cee ey We Nye fot 2 ene MINCH yf or A ET; z } : ; Ae aA res @ SUM ay ee " Rt eet ‘tie: 4® fires etree is oe ®\ NAKNEK = ee ear ee ASCE fig ‘ ie ale Bes \ ng aT, ) he aah ae WO NATIT me a Figure 57 “ 7 . | UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES. SCALE |. 250 000, AND OTHER OFFICIAL SOURCES. 150 MILES } aioe DATUM IS MEAly SEA LeveL > LEGEND bh @ CLIMATOLOGICAL DATA STATION Nice OPERATIONS AREA HEADQUARTERS as Oi Be DISTRICT FIRE CONTROL OFFICE ee) GUARD STATION | ie == PRIMARY HIGHWAY ACRES. AVERAGE NUMBER PER YEAR; ALL SIZE CLASSES. Pye sy FIRES PER MILLION 1950 - 1958 ON q Boe veh es Le Figure 58 on At e i UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1: 250000, AND OTHER OFFICIAL SOURCES 1954 50 150 MILES =r = £0 > 150 NILOMETERS = = Scan aan DATUM IS MEAN) SEA LEVEL — LEGEND CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION s==== PRIMARY HIGHWAY Bye FIRES PER MILLION ACRES, AVERAGE NUMBER PER YEAR, ALL SIZE CLASSES. 1950 - 1/958 MINA Zz CGRATH Beet a ae Oh & GJANNALLEN ae a5 id 7 7. 3 ea = 5 ny y ay, “7 C. oe wy boi (4. Meas es Z 7 a ee ‘ LP = " & SKILA 4 Princo fs. 2%, 5 hain ra “et * a: Aig (aE BY aint? [GG money ht +f @ ILIAMNA >). MoE cia Figure 58 CHAPTER 7 FIRE CASE HISTORIES Why do fires in Interior Alaska get so large so fast? What is the actual rate of perimeter and forward spread? What weather factors are as- sociated with various rates of spread? And, is the rate of spread significantly different between fuel types? Preliminary investigation of research needs showed an almost complete lack of recorded data in the form of weather, fuels, or behavior that would aid in answering these questions. In 1958 a case history study of fires in Interior Alaska was started. During that and the follow- ing year, two 2-man teams, equipped with port- able fire-weather stations (fig. 59), gathered data from 19 fires; case histories of seven are presented here (fig. 60). Figure 59. — Portable fire-weather station. 69 The most valuable data were collected dur- ing the free-burning period before control action altered the spread rate of the fires. Thus, data for several of the fires cover a period of only a few hours, even though the fires may have spread for a much longer time. Results of this study indicate that nearly all extreme behavior can be explained qualitatively but not quantita- tively. HEALY FIRE The Healy fire burned 40,320 acres because of continual high winds. Healy is on the lee side of a major pass in the Alaska Range, between the Anchorage-Susitna River area and the Ne- nana River-Fairbanks area. Prevailing winds augment night downslope winds and override daytime upslope wind tendencies. Nonuniform topography downwind may also have caused erratic local winds and eddies. The fire originated in a coal seam that had been smouldering for several years. At the time of discovery, midafternoon on July 4, 1958, it covered 50 acres. By 2300 it had increased to 100 acres, and was burning on steep, rocky terrain covered with black spruce, brush, and dense grass. Excerpts from the narrative report of the fire indicate the influence of the continual high winds in thwarting early control: The wind made it almost impos- sible to do anything for about the first two weeks of the fire... 34 of the time men on the ground couldn't keep ahead of the fire... After five inches of rain and four days since the last smoke, we felt rea- sonably safe and left the Healy wind tunnel. Weather and behavior records collected by the team after its arrival on July 8 showed that the major runs occurred on July 9, 10, and 11, although relative humidity was rarely below 50 percent and burning index was around 20. The worst burning condition prevailed on July 26 (32 percent relative humidity, burning index 44); however, since control was near there was no appreciable spread. One topographic feature hampering control of the fire was a bald moun- tain that caused the fire to split and form two heads. A note at the July 8/2200 reading indi- cates an interesting general wind situation: “The smoke is still being carried away by the fast surface winds, but as it reaches the flat country at the base of the mountain the smoke rises and forms huge cloud formations." The fire was declared under control August 1. on MURPHY DOME FIRE No single factor can be pinpointed as the major cause of this fire that scorched 13,300 acres. Broken topography to the lee of a broad valley, cumulus clouds and even thunderstorms in the vicinity, and high burning indexes all contributed at various times. This lightning fire started on July 2, 1958, and covered 3 acres at discovery time the next morning. When initial attack forces arrived 5 hours later, it was at 500 acres, and by evening was 1,500 acres. The primary fuel at first attack was heavy black spruce, with a light understory of grass, brush, and deadwood. The fire burned through some birch and aspen stands, and near the top of Murphy Dome raced through a gradually thin- ning tundra cover. Weather records show that either towering cumulus or mature thunderhead clouds were in the vicinity whenever the fire made a big run — a rather good indication of unstable air and downdraft conditions. The highest burning in- dexes (66 and 58) fell on the 2 days during which the greatest spread occurred — July 5 and 13) Several features of topography apparently affected the erratic behavior of this: fire. The wind directions recorded at the fire differ from those recorded at Fairbanks. Winds coming across the broad Tanana valley on both the west- ern and southern sides of the fire area were broken by the mountains in which the fire burned. The northeast-southwest flowing Gold- stream Creek and its steep tributaries further complicated the consistency of airflow. The whole topographic complex made it nearly im- possible to predict the path of the fire. The fire was declared controlled on July 21. 70 KENAI LAKE FIRE Extremely steep and long, narrow canyons converging at the head of the lake cause strong winds that exhibit daily reversals in direction; 3,278 acres was burned on this fire, primarily as a result of these winds. Local night drafts could have been quite gusty and strong and from al- most any direction during the time of the fire's rapid advance. The burning index, recorded at the lower end of Kenai Lake, climbed to 57 on the day of origin; this is critical for coastal Alaska. Clearing fires from homestead preparation and right-of-way construction have caused hun- dreds of acres of forest land to go up in smoke over the past 5 decades. A right-of-way clear- ing fire in National Forest land along Kenai Lake was very small when discovered and first at- tacked on June 10, 1959. The point of origin was in a stand of white spruce where consider- able moss was present; both the rate of spread and resistance to control were rated as high. By evening of June 13, the fire covered about 2,000 acres, extending along Kenai Lake for 7 miles and up a 75-percent slope for a mile or more. The major part of the fire burned in good quality black spruce timber. The fire had pretty well run out of fuel on the upper reaches of this steep mountainside, but it was burning at both the left and right ends. The condition of the fire at this time can best be described by quoting from the fire-behavior team's report: ... the fire was burning at about 120 chains per The fire was crowning in mostly black spruce timber with a northeast wind blowing at 10 miles per hour behind it. There were small spruce needles falling all over hour. the ground as far as 2 miles ahead of the fire... At 0800 on June 14, the 39 percent relative humidity and the 9 percent fuel moisture indi- cated afternoon burning conditions would be unusually bad. However, the fire made no par- Fair weather cumulus clouds were overhead from before 1600 until after 1800. At 1730 the wind shifted from a prevail- ing northeast direction to southwest, with a considerable increase in velocity. Line was lost at both ends of the fire and along the lakeshore ticular big gains. COMPILED FROM TOPOGRAPHIC SER! LEGEND === PRIMARY HIGHWAY UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E OLOGICAL SURVEY ALASKA RECONNAISSANCE ALE 1.250.000. AND OTHER OFFICIAL SOURCES DATUM IS MEAN SEA LEVEL CLIMATOLOGICAL DATA STATION OPERATIONS AREA HEADQUARTERS DISTRICT FIRE CONTROL OFFICE GUARD STATION FIRES ON WHICH SPECIAL STUDIES WERE MADE } we a Oy : Dae SPAETH re su Figure 60 Barrow.) > UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ALASKA MAP E COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE? TOPOGRAPHIC SERIES, SCALE 1: 250.000, AND OTHER OFFICIAL SOURCES 1954 180 MILES pale DATUM IS MEAN SEA LEVEL _ LEGEND ® CLIMATOLOGICAL DATA STATION. % OPERATIONS AREA HEADQUARTERS # DISTRICT FIRE CONTROL OFFICE 2% GUARD STATION eos == PRIMARY HIGHWAY ¥ ge! oe Me oud AY Ase ae. ‘ MW) FIRES ON WHICH SPECIAL Ar We i ne ON ee. STUDIES WERE MADE Nt # dh he * vs BRGY 4 iy MUD gee, ’ RE bs 4 tay Ra o yerson \ y 5 BUFFALO CENTER #) Ra aS Hy, SLRS sn WL MAE en Wide, “F TANACROSS he yy VSN TAN 3 i, Para Dy SAE = Bk iis BE WesWe ANCHORAGE /” “YP SKILAK LAKE EIS Mapes eea LA2>, tf, : fs % { * ee 3 A N ee @# HOMER See RES tb AGG = SSR = s © NAKNEK WY Figure 60 ea g -eameaige yi ay, nana A i. i featge: Gerrneee | Lp e we OR athe S| isi ae ee 4 es rete D» i (\ | . i | A Roeity if , LLeep | Ss a | i.) 6S hea » | \{ a RSA 2 P = A rr LO O/ f/f [i © SCALE 1: 250,000 0 Figure 61. — Healy fire vicinity. 71 SCALE 1:250000 O 5 MILES mest Meer Figure 63. — Kenai Lake fire 1 year after it burned. road, and many summer homes in the Snug Harbor vicinity were endangered. The fire be- came extremely active for a short while but slowed down as soon as the wind slackened. The wind shift on the fire may have been caused by a major shift in pressure patterns aloft; evi- dence for this might be the disappearance of small cumulus clouds from the area. A special fire-weather forecast could possibly have warned the fireboss that such a situation might occur. This was the last significant advance of the fire; it was declared under control 2 days later. COLORADO CREEK FIRE Brisk winds, highly flammable fuels, steep topography, and unprecedented critica! fire weather all contributed to the difficulties of pre- dicting fire behavior and of taking adequate control measures on this 6,000-acre fire. This fire is thought to have been set by an incendiarist on June 17, 1959. By early morning on June 18, 100 acres of muskeg had burned and burning was intense on each of the 3 days fol- lowing ignition. Such critical fire-weather factors as those listed below were never before re- corded in Interior Alaska: USFS Fuel Moisture Relative Date Stick Slat Temperature humidity Percent Degrees F. Percent June 18 Tf, 2.4 86 24 19 6.9 YA 19 20 Fal 1.6 83 21 On June 18, a brisk gusty wind began by 0700 and persisted throughout the day. Before 1300, surface winds carried the smoke away near the surface; but after that time the column rose rapidly to extreme heights. Fair weather cumulus were present from 1300 on. By 1400 the fire was racing through muskeg at the rate of 60-chains-per-hour forward travel. Fast spread continued for about 2 hours. On the morning of June 19 the sky was clear and wind speeded up to a maximum of 8 miles per hour. The fire jumped the control line and headed out at a rate of approximately 400 chains per hour. Black spruce became part of the fuel at the fire's head. The smoke column rose for several hundred feet, then flowed with the upper wind; however, as the day went on, the fire slowed down and the smoke column tended to toadstool; at this time the cirrus and SCALE 1:250 000 Figure 64. — Kenai Lake fire vicinity. 74 5 MILES SCALE 1:250 000 75 igure 65. — Colorado Creek fire vicinity fair weather cumulus clouds did not appear to have much movement. June 20 was another bad day. Altocumulus castellatus clouds (often a forerunner of thunder- storms and unstable air) were noticed from mid- night until about 0900, but no cumulus develop- ment beyond fair weather stage followed. At 0800 altocumulus lenticularis appeared and the wind increased. At 1100 the fire jumped a wide control line and raced up a 90-percent slope through a black spruce stand at a rate of 140 chains per hour. After it burned out the large patch of black spruce it crept slowly in the sur- rounding birch stand. This midday action was the last period of rapid spread; the fire was de- clared under control by midafternoon June 23. The entire 3-day period of record was char- acterized by temperatures about 10° F. above normal. Wind direction was predominantly from northeast on June 18, east on June 19, south- east on June 20, and east again on June 21. Average cloud cover was 0.7. Gusty winds caused some of the rapid advances by whipping backfires across the control lines. Presence of lenticular clouds on June 20 indicated high winds aloft. These, coupled with the combina- tion of the local general wind direction of south- east and the normal ofternoon tendency of wind to flow up-canyon in the side draws, may have helped the fire take advantage of local highly flammable fuel concentrations and race through these at unexpected times. LAKE 606 FIRE Thunderstorm downdrafts were the appar- ent causes for short separate periods of vicious behavior of this fire, which burned over 1,400 acres. The Lake 606 fire was thought to have been _ started by lightning on June 19, 1959. It was discovered the afternoon of June 20 by patrol plane and was estimated to cover 30 acres. Initial attack forces arrived in the early morning of June 21 and soon found two fires totaling 100 acres; these burned together at 1400. Thunderheads persisted in the vicinity dur- ing that afternoon. Fuel moisture of the sticks and slats was 10 and 7 percent, respectively; maximum temperature was 76, and the lowest relative humidity was 44 percent. Wind was 76 from the north or northeast except at 1600 and 1700, when it came from the southwest with increased gustiness and velocity, up to 25 miles per hour. The fire-behavior team mentioned it was difficult at this time to tell which end of the fire was the head and which was the rear. To quote their 1600 report: About 1530 lots of unusual things started happening. The wind was very variable. It could sometimes change di- rection completely and sometimes it was at a standstill. There were some whirlwinds all along the fire line... The smoke was rising fast and ex- tremely high, becoming a part of a big toadstool directly overhead. It was im- possible to determine atmospheric conditions from where we were be- cause of the smoke. We did hear thunder in the SE. At 1700 the report continued: Between 1600 and 1700 we had a very unusual big blowup on the fire. The smoke was rising extremely high and forming a big toadstool directly over the fire. The fire was completely out of control, burning at rate of about 4 chains per minute (240 chains per hour). It only burned about 30 minutes at this rate. At 1640 it began to rain and about 1715 the wind began to let up. At the two places on the fire where most of the activity was taking place there was small black spruce and lots of brush. The fire was sweeping through the trees and leaving the tundra and grass to burn later. At 1645 lightning appeared in the SE. Rain stopped the fire at 1,400 acres. Atmospheric instability and thunderhead downdrafts probably contributed heavily to the extreme behavior of the fire. Black spruce also appeared to be very conducive to crown fire behavior. Fires behaving as this one did can easily become “‘killers.’’ To prevent such possible tragic events a better understanding of the ‘‘whys’’ must be learned, supervisory personnel on fires Figure 66. — Lake 606 fire vicinity. C6 must be trained to anticipate such behavior, and more reliable methods for prediction must be developed. STONY RIVER FIRE Unobstructed horizontal continuity of fuels had much to do with the rapid advance of this fire. Unexpected shift of wind direction and ve- locity could have resulted from mature cumulus clouds, but few were noted; possible passage of a frontal movement could also have contributed to the large final area of 8,000 acres. The lightning fire started on June 22, 1959, and by the next afternoon it had spread to an estimated 5,000 acres. The country was flat to rolling; surface weather conditions gave no outward indication of bad fire weather. The wind varied from 5 to 12 miles per hour and was gusty; but even so, the smoke column rose rapidly and formed a towering cumulus cloud. A change in the gen- eral atmospheric situation may have influenced a shift of wind at 1330 from northerly to southerly; the wind aloft caused crowning and a spread rate of 18 chains per hour. Towering cumulus clouds that were observed at 1315 could also have caused the wind shift and resultant fast spread. From 1550 until nearly midnight the surface wind blew from the west, but the clouds came from the southwest. In 9 hours’ time the wind swung around clockwise about 270°. The greatest spread rate was 33 chains per hour at about 1700. No extreme behavior occurred on June 24. The fire spread both to the north and the south on June 25. Mature thunderheads devel- oped by 0800 and persisted until noon, when only fair weather cumulus were reported. A trace of precipitation fell during each 2-hour period from 0800 through 1400; this indicated that thunderheads may have been present later into the day than the record showed. Winds were steady to gusty from 4 to 10 miles per hour from the northwest pushing the fire to the south, but at 1600 the wind shifted to a southwesterly direction and caused trouble on the north end of the fire. The smoke column first rose lazily and spread out gradually, but after 0900 the surface wind carried the smoke away before it rose. Locally unstable atmospheric conditions may 78 have accounted for most of the high rates of spread; fuel moisture, relative humidity, and burning index were mild all day. After June 25, the fire spread very little. Coupled with a variety of weather condi- tions, the fuels — primarily black spruce — were capable of carrying the flame front with ease. The relatively flat rolling country with few ob- structions also permitted the fire to travel un- hindered. From the limited information collected, it is hard to know whether the wind shifts were of local or general nature; however, upper air soundings at Bethel, 175 miles southwest of the fire, indicated a general southwesterly flow of air that was convectively stable at 1400 on June 24, in neutral equilibrium at 0200 on June 25; but at 1400 on June 25, layers of air were be- coming convectively unstable. The final area was 8,000 acres, about 5,000 acres of which burned on June 23. HUGGINS ISLAND W-10 FIRE Three major runs were observed on this fire. Steep slopes and heavy black spruce fuels were associated with all three. Brisk winds acceler- ated one of the runs, and thunderstorm cells in- fluenced another. The fire was lightning caused on June 19, 1959, attacked on June 24 when it was already 4,500 acres, and abandoned on July 1. It finally burned out at an estimated size of 50,000 acres. During June 25, both towering cumulus and altocumulus lenticularis clouds were present; some precipitation fell at 1630. At about 2000 the fire, which had been crawling through tundra, reached a black spruce stand on a 7/5-percent slope and raced through it at about 90 chains per hour; the average spread for a whole hour was 45 chains. There was no special note of increased or erratic wind; no cu- mulus clouds were present; but the smoke column changed from rising lazily and spreading out, This change in the smoke column characteristic may to being carried away by surface winds. have been an important clue to the sudden rapid spread of the fire, but the changes in slope and fuel type were also pertinent to the cause. There might also have been a topographic influence on local wind flow at that time of day. | SCALE 1:250000 Figure 67. — Stony River fire vicinity. 79 fe A = : : oO 3 wo N 5 Coen a 53 Lu C =) < ©O 7) On the morning of June 26, after a change from steady, light northeasterly wind to a vari- able wind, and under moderate fire-weather and clear-sky conditions, the fire began crowning at 80 chains per hour up a 75-percent slope con- taining black spruce. At 1000 all the weather conditions worsened, many dust devils occurred, cumulus clouds began to form, the smoke column rose rapidly and high, but the fire slowed to 20 chains per hour on a 35-percent slope, still in black spruce. The wind was now from the north and continued there all day. The fire continued to advance but not with extreme behavior char- acteristics. At 1600, however, to quote the fire-be- havior report, ‘A whole north-south wall of flame is moving west over a ridge at a fantastic rate — possibly a good 5 miles per hour. No warn- ing — the whole ' mile of flame started within 3 minutes.'’ The smoke column continued to rise for some distance, then toadstooled. There had been no noticeable weather, fuel, or topographic change (21- to 50-percent slope) to cause this erratic behavior; nowever, the 1800 observation mentions fully mature thunderheads with virga in the vicinity. Maximum wind velocity at the weather station, though, was only 11 miles per hour. At 1930 the wind shifted from north to southeast, the fire subsided and remained quiet during the night. The fire was now about 13,000 acres in size. Since the available firefighting crew was so small and the extended period of fire weather was so adverse, the fire was finally abandoned in late evening on July 1. More complete weather observations and intensive study of the atmospheric conditions might have led to a better explanation of the fire's rapid spread. SUMMARY Topography to windward of the Healy fire forms a saddle through which wind velocities are usually greatly increased. This fact is the major reason for the fast spread and difficult control of the fire. The broken topographic complex on the lee side of a broad flat valley, high burning index, thunderstorms, and instability all contributed to the irregular and difficult time for predicting be- havior of tne Murphy Dome fire. One day the 81 fire spread for several hours at a rate of 40 chains per hour. Topography surrounding the Kenai Lake fire vicinity is extremely rugged and consists, in part, of steep canyons converging on the upper end of the lake. The resultant strong diurnal winds reverse their direction in morning and evening; altered atmospheric conditions also violently af- fect the wind pattern. The diurnal effect caused serious trouble on one day, and a front moving through caused considerable loss of line on an- other day. The worst fire weather of all the fires re- ported here occurred on the Colorado Creek fire. The brisk winds that were altered by steep to- pography, highly flammable fuels, and generally critical fire weather all contributed to the dif- ficulty of predicting fire behavior and taking ap- propriate control measures. A spread of 140 chains per hour in black spruce was recorded for a brief period. The initial run of the Lake 606 fire was caused by strong winds. The greatest spread, however, was apparently caused by thunder- storm downdrafts and unstable atmospheric con- ditions. Constant rapid spread of the Stony River fire was aided by unbroken horizontal fuel continuity and relatively unstable air associated with a frontal activity which changed the wind direction a total of 270 degrees. The fire traveled at a rate of 33 chains per hour at times. Thunderstorm downdrafts may have caused a %y-mile section of the Huggins Island W-10 fire to advance briefly at a rate of 320 to 400 chains per hour. A local wind-topography-black spruce fuel situation may have caused another rapid advance of 45 to 90 chains per hour. A wind switch accompanied by local instability accounted for still another advance rate of 80 chains per hour. Rough topography, variable and gusty surface winds, evidence of high winds aloft, and local atmospheric instability all con- tributed to periods of extreme fire behavior. From these case histories very few specific conclusions can be drawn. However, for the first time some systematic measure was made of the weather, topography, and fuel conditions during actual free-burning periods of wild fires in Interior Alaska. The results point up these things: (1) Most wildfire activity can be measured and explained; (2) more sophisticated methods will in the future add quantitative information 82 to the predominantly qualitative data recorded in this study; and (3) the groundwork has been laid for answering the four questions at the be- ginning of this chapter. CHAPTER 8 FIRE CONTROL Timber losses have approximately balanced timber growth in unexploited Interior Alaska. Future demand to harvest part of the crop each year will require an increase in net growth to re- place this removal. Besides, the national econ- omy will demand a continuing increase in the future allowable cut. How much should be spent to protect this important resource? Where is the breaking point between the ratio of loss and damage versus the cost of protection? No economic study has been made to ascertain just how much Alaska is worth in terms of what should be spent to pro- tect it. Helmers (1960, p. 470) states, “Fires are so much a part of the summer scene that there is also the psychological problem of getting pub- lic recognition of the economical losses due to fire.’ A close review of the history of our re- source protection effort and a good look at long-range needs show the necessity to materi- ally reduce forest fire damage in Alaska. Until July 1939, organized forest fire con- trol in Alaska was nonexistent. Then the terri- tory received $37,500 to establish the Alaska Fire Control Service. Early efforts were confined to suppression of man-caused fires within sur- face striking distance of Anchorage and Fair- banks. Throughout development of an _ effective firefighting force, several major problems have persisted. The vast area and the contrastingly small, concentrated population have made early detection difficult; the lack of access to remote forest and range lands compounds the logistics of reaching fires and supplying crews. As tourist numbers increase, so does caused fires. incidence of man- An increasing awareness of the values at stake and of the need for better pro- tection has mandated the fire control organiza- tion to use every means available to reduce the losses (Robinson 1960). Since inception of the Alaska Fire Control Service, great strides have been made toward control of the major portion of forest fires in Alaska. Begun under the old General Land Of- fice, the fire control organization is now oper- ated as an integral part of the Bureau of Land 83 Management, which has responsibilities for pro- tection and management for more than 95 per- cent of the State's area. Protection of much of this land will remain the responsibility of the Bureau of Land Management for years to come even though the State will, within 25 years, as- sume title to more than 100 million acres. In 1955 the Bureau of Land Management developed a comprehensive forestry program for Interior Alaska. The four major management objectives are: (1) multiple use management of the entire forest resource complex rather than timber management alone, (2) water resource protection and development, (3) increased utili- zation and development of the present timber resource, and (4) protection of the public's vested interest in the forest and range resources in Alaska from destruction or damage from fire, insects, None of the first three management objectives can be met with confi- dence until the fire protection organization can assure, within reasonable limits, a continuing forest cover. Robinson (1960) proposed a goal of not more than 100,000 acres of burned area per year. Basic barriers to early detection, at- tack, and control of fires must be identified and overcome. FIRE CONTROL ORGANIZATION PRESUPPRESSION Regardless of the severity of any one fire season, a well-developed fire control organiza- tion containing basic personnel and equipment must be ready to handle an average bad season. Perhaps the job confronting fire control personnel for Interior Alaska can best be described by comparing it with another fire control group, Region 1 of the U.S. Forest Service: and disease. Interior Alaska Region 1] Interior Alaska compared to uses | BLM Region | Acres protected 32,000,000 225,000,000 7 times Acres. burned 4,467 1,119,130 250 times Number of fires 1,069 254 25 percent Number of fires per 33 11 3 percent million acres Fire personnel, man-years? 348 38 11 percent Number people per 4.9 4 8 percent square mile }Montana, northern Idaho, northwest South Dakota, and northeast Washington. 2Regularly assigned positions including fire control aids. Bases and Warehousing Major operational bases and warehousing facilities are at Anchorage and Fairbanks, the only two cities capable of furnishing manpower, food, equipment, supplies, and services neces- sary for launching and supporting fire crews in the field. These are augmented by a few sec- ondary permanently manned bases located at strategic support centers. In addition, several fireguard stations, manned seasonally, are situ- ated from Skilak Lake on the Kenai Peninsula northward to Fort Yukon just north of the Arctic Circle. The long time required to deliver many supplies (retardant chemicals for instance) makes it imperative to anticipate such needs as long as one season ahead of expected use. Most equipment, tools, and supplies are packaged and stored in six-man units — a Grumman Goose load of firefighters. Develop- ment of new tools and equipment for fighting fires in the Alaskan fuel complex has lagged seriously. Dozers, tankers, and pumpers are used where available and where topography and soil along the fireline permit. Shovels and pulaskis are the old standbys for handtool work. New hand and power tools are urgently needed to help offset the relative scarcity of personnel, the difficulty of terrain, and the remoteness that gives fires such a headstart. Dispatching Most dispatching of men, equipment, and materials is handled at Anchorage and Fair- banks. Nearly all smokejumping and a major part of retardant chemical attack operations are controlled from Fairbanks. Dispatching involves considerable advance planning, preparation, and training. Even pilots of the contract retardant planes require orientation and training by the dispatcher staff. All aircraft use is controlled by the dispatcher and chief pilot in order to attain greatest value from each plane. Effective dispatching depends upon a highly reliable communications system. Trunkline tele- phone service is excellent, but is limited to the large cities and to a few places of habitation along the main highways. All other communica- tions are by radio. Airplanes need the most complex set of equipment as pilots depend on 84 radio for navigation and safety as well as for tight control on fire missions. All stations and a large share of vehicles are radio-equipped: VHF-FM for air-ground work; VHF-FM and HF- AM for vehicle and station use. Deployment of men and equipment during the fire season must be based upon information about fire occurrence. Since a large percentage of man-caused fires occurs in May and early June, men, tankers, dozers, and other ground equipment are aimed at control of fires near habitation centers and areas of agricultural de- velopment. Later, all the aircraft — whether for patrol, smokejumping, chemical attack, or sup- ply — must be in constant readiness to attack lightning fires anywhere in the State. Manpower The supply of manpower in Alaska is small, and the distribution in respect to recruiting fire- fighters is poor. Even though Alaska’s popula- tion has increased fourfold in the past 40 years, the 1960 census records a total of only 226,167 persons (four-fifths the population of Nevada). The tabulation below shows the uneven distribu- tion of people; only about 100,000 persons re- side outside of the Anchorage and Fairbanks vicinities, and many of these are in the southeast coastal area. Climatic Geographic Approximate division division population Maritime zone Southeast, South Coast, 56,000 Aleutians Transition zone Copper River, Cook Inlet, 106,000 Bristol Bay, West Central (includes Anchorage) Continental Interior Basin 49,000 (includes Fairbanks) Arctic zone Arctic Drainage 15,000 A small part of the regular fire control per- sonnel are year-round employees, but most of the fire dispatching and overhead employees are seasonal. Most of them enter duty in April or May and remain until September. They are the well-trained nucleus that leads the attack on fires throughout the summer. The actual firefighters come from two sources — Indian villages and the open labor market. The natives and Eskimos are excellent firefighters. Their villages are sufficiently scat- BLM B BLM ic USFS Figure 69. — Base facilities: A, fire headquarters, Fairbanks; B, smokejumper center, Fairbanks; C, dispatch room, Fairbanks; D, McGrath station; E, Skilak Lake guard station. 85 tered so that groups are often close to fires and can be recruited rapidly for early attack. They learn quickly and fit well into fireline organiza- tion. Also, they are physically able to stand backbreaking work for many days at a time. The pickup firefighters from the open labor market are of similar caliber to those found anywhere else; however, a few of them do re- turn season after season and become topnotch workers. Successful in western United States since World War Il days, smokejumping began in In- terior Alaska in 1959 with 16 jumpers. Setting up a smokejumper center in Fairbanks was a major undertaking. Everything from a loft-dor- mitory building to sewing machines, from ac- quiring a DC-3 to modifying the doors of a Grum- man Goose had to be done to make the jumper force effective. Retraining dispatchers in new procedures and transportation methods was also necessary. Well-executed presuppression work in this new phase of fire control paid off when the actual suppression load began to increase. Transportation Of Alaska's 5,000 miles of highway, 3,000 are blacktopped, 2,000 are graveled. access roads go into homesteads, mining prop- erty, and recreational sites, but the actual mile- age of these roads is very small. However, since most man-caused fires are along the highways or on homesteads (fig. 57), a far greater number of trucks, pickups, and tankers is used than one would suspect by looking at road data alone. Private Aircraft are the hard core of the firefighting attack force. As one official put it, ‘The possibil- ity for successful fire control started the day we These short-field amphibious planes can land on small lakes or sloughs close to fires; hence they are constantly used for patrolling, servicing and sup- plying, making initial and reinforcing attacks, and for smokejumping. Single engine, 4-place planes are kept busy on patrol, scouting, in- spection, and administrative use. A Douglas C-47 (DC-3) is used primarily for smokejumpers; but it can also move equipment, supplies, and non- jumping firefighters. A P-51 fighter plane carries the observer for long-range detection and scout- ing; it is also used as lead plane for chemical retardant attack. received our three Grumman Gooses."' 86 Charter and contract planes carry all the overload while the fire season is in full swing. At the peak of the season, one sees the usual assortment of larger chemical retardant applica- tion planes, several makes of helicopters, and both wheel and float type planes of the single engine, 4-place category. The numerous Alaskan commercial airlines furnish much of the heavier point-to-point hauling. When fire conditions become critical and commercial equipment is no longer available, the military forces contribute many hours of fly- ing. Heavy point-to-point hauling is done by planes in the C-123 class; helicopters —- even the large double-rotor type — often do yeoman duty during crucial times. DETECTION? The critical need for early detection of fires has been emphasized several times. A small crew can usually (not always by any means) handle a fire if they can attack before it begins to take over its own destiny. Prior to about 1957, aerial detection was limited for a practical reason: The attack force was not large enough to act on more than a small percentage of the fires; so there was no point in detecting all the fires that did start. The advent of retardants and smokejumpers now makes early detection of all fires imperative if these two new weapons are to be of maximum value. All the means of detection credited above are somewhat haphazard, and at best are a poor substitute for a continuous, trained detec- tion organization. The Bureau of Land Manage- ment has, since 1959, chartered a P-51, Mustang fighter plane to follow in the wake of thunder- storms in order to locate possible resultant fires. This procedure has helped early detection of many fires, but it has certain serious drawbacks: One plane cannot adequately patrol 150 million (the area of Montana and Idaho com- bined); an observer cannot locate all small fires acres from a fast-moving, high-flying plane; accurate 9Statistical analysis of time elapsed between origin of fires and their discovery proved unsuccessful because too many data were lacking on the fire reports. Only about one-third of the large (Class E) fires could be used; this fact presumably in- fluenced the results to show that longer lags in discovery time did not result in larger fires. The question will have to remain a matter of conjecture until factual data are collected on the behavior of free-burning fires: from the time of origin. Cc USFS Figure 70. — Transportation: A, foot travel is slow, often impossible; B, loading a Goose for fire run; C, air supply — Goose to small float plane. 87 UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY ATe ALASKA | ete ce MAP E COMPILED FR VEY ALASKA RECONNAISSANCE TOPOGRAPHIC E1:2 AND OTHER OFFICIAL SOURCES we tes oie tah) : DATUM IS MEAN SEA LEVEL LEGEND vA CLIMATOLOGICAL DATA STATION Nowe OPERATIONS AREA HEADQUARTERS (fee DISTRICT FIRE CONTROL OFFICE oe eg GUARD STATION ee === PRIMARY HIGHWAY ae AREA OBSERVED BY : COMMERCIAL AIRLINES GREEN 1 -/0 FLIGHTS PER WEEK Mg eo BROWN 11-20 FLIGHTS PER WEEK RED MORE THAN 20 FLIGHTS PER WEEK SOURCE: /959 AIRLINE SCHEDULES AB ye STS STOR SP DP AATI Tem coe ae Figure 71 uy “w 1 ay on KILAK LAKE 2 ai Fo ae UNITED STATES DEPARTMENT OF. THE INTERIOR GEOLOGICAL SURVEY = ALASKA See MAP E aN COMPILED FROM THE GEOLOGICAL SURVEY ALASKA RECONNAISSANCE TOPOGRAPHIC SERIES, SCALE 1: 250 000, AND OTKER OFFICIAL SOURCES. — 1954 \ On Serine eraser” \ ano \ ‘ DATUM IS MEAN SEA LEVEL ee _ LEGEND wl \ se ® CLIMATOLOGICAL DATA STATION w® OPERATIONS AREA HEADQUARTERS # DISTRICT FIRE CONTROL OFFICE e. $ &® GUARD STATION een =— PRIMARY HIGHWAY eS AREA OBSERVED BY \ - COMMERCIAL AIRLINES GREEN 4-10 FLIGHTS PER WEEK ak BROWN 11-20 FLIGHTS PER WEEK RED MORE THAN 20 FLIGHTS PER WEEK SOURCE 1959 AIRLINE SCHEDULES pry? 6-93 ~ et Le se nluureyh at Mt BE Het Per RL, 1f z ts : a 2 5 SS ES — —— — REET ee er ee ee teenies OO DLL AAA ALAA LL SS Figure 72. — Early detection of this small lightning fire will contribute to rapid control. description and location of current thunderstorm cells or systems is not yet feasible; and, because of its speed such a plane is often diverted from its primary detection mission to be used for re- connaissance of going fires and for lead plane duties on retardant chemical attacks. The lighter planes which are also used occasionally for pa- trol are dispatched to lead plane duty whenever possible to permit the P-51 to continue its recon- naissance work. Recent advances in development of elec- tronic devices may make it possible to provide a reliable system for tracking storms, locating fires, and mapping going fires. Certain types of radar can identify mature thunderstorm cells. Sferics receivers are being developed to further determine whether an electrical disturbance is present (Battan 1959). Airborne infrared map- ping devices are now being investigated for use in the actual locating and mapping of fires (Hirsch 1962). SUPPRESSION Preparation for an expected bad fire season in Interior Alaska is a tremendous job, but it must be done thoroughly so that the subsequent suppression effort will be adequate. Method of Attack Fire control tactics in Interior Alaska are similar to those used elsewhere. Logistically, at- 89 tack on fires accessible to motor vehicles is rela- tively simple. Initial attack on fires hundreds of miles from the source of supply requires ingenuity and wise use of every facility feasible. Except for longer time and distances involved, the fol- lowing procedure follows closely those used in other States: As soon as a fire is reported, the dispatcher sends chemical retardant planes. At the same time he dispatches smokejumpers. Then, ground forces are sent to reinforce and re- lieve jumpers. Their travel may be by land plane to a small field, thence by amphibious plane to a body of water near the fire, and possibly by helicopter to the fireline. Subsequent loads of chemicals for tactical support are often ordered when conditions indicate the need. As an example of the effectiveness of this type of rapid attack, some 1959 statistics follow: Of all fires upon which retardant was dropped, 35 percent was within 50 miles of the base, 43 percent between 50 and 100 miles, and 22 per- cent between 100 and 200 miles; an average of seven loads was dropped on each fire by planes traveling a mean one-way distance of 85 miles. The application of chemical checked the fires’ spread to an extent that firefighters controlled 85 percent of them at the same size class as when the retardant was applied. Smokejumpers in 1959 traveled as far as 472 miles to reach fires, but the average distance was 250 miles. Jumpers controlled 36 fires with an average force of five men per fire, and con- trolled 94 percent of them within the same size class as when attacked. Distance Traveled to Fires Analysis of individual fire reports showed only the following general relationships between distance traveled according to final fire size, and whether action was taken: Fifty-six percent of all reported fires occurred within 100 miles of head- quarters. Sixty percent of action fires occurred within 100 miles compared to only 20 percent of those on which no action was taken. Only 12 percent of action fires occurred at distances greater than 200 miles compared with 39 per- cent for no-action fires. One-third of the fires larger than 300 acres are farther than 200 miles away from headquarters. More than two-thirds are farther than 100 miles away. This situation will always prevail simply because it takes Table 16.—Percent of fires controlled within each class of time lapse from initial attack by final size class (Av. 1950-58) Final size Time lapse (hours) class 0-1 1-2 2-3 3-6 6-12 12-24 24-48 48-72 72+ Percent A 73 12 5 8 1 0 B 31 WA 13 16 8 8 4 1 2 (é 1] 8 9 23 19 12 8 3 7 D 3 5 13 10 22 16 13 5 13 E 1 1 2 5 11 11 16 12 4l Av. 30 11 9 14 10 8 6 3 9 TLess than 1.0 percent. longer to go greater distances. But when greater Time From Attack to Control distance from headquarters is coupled with Table 16 based on records of 986 fires con- longer time between fire origin and detection, firms what one would expect to be the relation between the length of time required to control a fire and the final size of the fire; namely, the longer it takes to bring a fire under control, the pay its way. larger the final acreage will be. only larger fires yet can be expected. Again re- duction of detection time would far more than Figure 73. — Such large fires are difficult and expensive to control. 90 Figure 74. — Aerial fire attack: A, smokejumpers drop on Christian Village fire, 1960; thin diagonal line in upper right is strip of retardant; B, timely jumper attack may assure early control. 91 Figure 75. — Fighting fires: A, handline construction is still the mainstay; B, 92 military eauipment assists in emergencies. The number of extra-period fires measures two things — effectiveness of the fire control organization, and severity of the fire season. An extra-period fire is one not controlled by 10 A.M. of the day following discovery. The BLM fire re- port data allowed only the following approxi- mation to be attained: a fire not controlled with- in 24 hours from initial attack. With this in mind, the figures comparing Interior Alaska (1950-58) with Region 1, USFS (1954-60) are re- markably close. Ratio of extra-period fires to Size of fire total number of fires Interior Region ] Alaska USFS Percent 10 acres or less 4 6 More than 10 acres 36 35 However, if the Alaska data were based on the time between discovery and control, the per- centage of extra-period fires, for the larger fires at least, would certainly be much greater in Alaska. Forward Behavior of Fires at Time of Attack The importance of early attack is illustrated in table 17. Usually fires with large final size are more violent in behavior at time of attack than small ones. Outstanding extremes in the spruce type are indicated by the fact that 70 per- cent of Class A fires are smoldering when at- tacked, but 47 percent of Class E fires are crown- ing when attacked. If fires could be reached while still small and before they start to run, the total control effort would be considerably les- sened, as would also the loss and damage. That goal can never be completely reached, as some fires may begin running and crowning almost immediately after they start; however, this infor- mation about behavior must be kept in mind as an important factor in both fire control planning and dispatching. Table 17.— Forward behavior of fires in spruce type at time of initial attack by percent within each behavior class and by size classes (Av. 1950-58) Final size Behavior class Smoldering Creeping Running Spotting Crowning Percent A 70 Si] 12 25 7. B 19 39 4] 25 17 C 18 22 19 19 D 5 5 12 10 E ve 20 19 47 FIRE AS A MANAGEMENT TOOL Use of fire in forest management is at times a controversial issue, but many protection and silvicultural objectives that could not be attained economically by any other means are being achieved through proper use of fire. Helmers (1960, p. 467) states, primarily in reference to southeastern Alaska, but possibly for many parts of Interior Alaska: 93 The possibility that fire can be used for silvicultural purposes is pure conjecture at this time. However, there is a need for reduction in slash volumes to reduce the physical impediment to regeneration as well as to reduce the fire danger in newly regenerated cut- ting. The seedbeds in cutover areas can be improved to advantage. These fac- tors alone make controlled use of fire a tool worth investigation. Figure 76. — Use of fire: A, slash hazard, Kenai Peninsula; B, timber resource suffers from poor planning; C, example of current practice of windrowing slash resulting from land-clearing operations. 94 Lutz (1960) recognizes that fire properly used can, even in boreal forests, become a valu- able silvicultural tool. He does not believe that the present forester or wildlife manager has suf- ficient knowledge *’ . to enable him to use prescribed burning on anything more than a purely experimental basis. There is a great oppor- tunity and need for research on this problem’ (p. 460). He also proposes investigating the use of fire to manipulate the position of the perma- frost table for silvicultural benefit. Ecological research performed within boreal forests in Sweden indicates results similar to those in Interior Alaska. Uggla (1958a), in com- paring the effects of controlled fires and wildfire, states that controlled burns on slightly moist ground is the most efficient method of activating humus materials for natural seedbed prepara- tion. He further states, ‘A feeble forest fire, on not too dry raw humus ground, can be compared Sp) with a controlled burning, but on poor, dry soils, uncontrolled forest fires can have devastating effects. . . . On such soils the activating effects of the fire soon disappear. Since also the addi- tion of litter will be very inconsiderable for a long time, degeneration of the forest soil often results’ (p. 5). Prescribed burning techniques for safe and effective land clearing in the Fairbanks area were explored by Johnson (1958, 1959) and Gettinger and Johnson (1959); they found it quite feasible to obtain a good clear burn with- out endangering the surrounding woods, but only if certain sound practices were pursued. As yet untapped are means for fully using fire as an effective tool in furthering forest management objectives. Research in fire and silviculture should aid in determining when and how fire should be used and when it should not be used. REFERENCES Anonymous. 1961. City on top of the world. Pt. 2. In Anchorage ‘Everybody flies." Alaska Sportsman 27 (2): 25-34. 1961. The world almanac and book of facts. 896 pp. New York: New York World Telegram and Sun. Arctic Weather Central, 11th Weather Squadron. 1950. *Climate, weather and flying conditions of Alaska and eastern Siberia. Elmendorf AFB Proj. 12B-1, 52 pp., illus. Barrows, J. S. 1951. Fire behavior in Northern Rocky Mountain forests. U.S. Forest Serv. North. Rocky Mtn. Forest and Range Expt. Sta. Station Paper 29, 103 pp., illus. Battan, Louis J. 1959. Radar meteorology. 161 pp., illus. Chicago 37: Univ. of Chicago press. Beall, H. W. 1949. An outline of forest fire protection standards. Canada, Dept. North. Affairs and Natl. Re- sources Forestry Branch, pp. 82-106, illus. (Reprinted from Forestry Chron. 25 (2), 1949.) Besley, Lowell. 1959. A preliminary national program of forest fire research for Canada. Canad. Pulp and Paper Assoc. Woodlands Sec. Ann. Meeting Index No. 1902 (F-3), 8 pp. Buckley, John L. 1957. Wildlife in the economy of Alaska. Alaska Univ. Biol. Paper 1, (Revised), 33 pp., illus. Bureau of Land Management. 1955. *Forestry Program for Alaska. U.S. Dept. Int., 89 pp., illus. Dachnowski-Stokes, A. P. 1941. Peat resources in Alaska. U.S. Dept. Agr. Tech. Bul. 769, 84 pp., illus. Elmendorf Forecast Center Headquarters. 1953. *Local forecasting studies. (For 7 Alaskan and Canadian stations). USWB, USAF, and USN station forecasting staffs for Elmendorf Forecast Center Headquarters. Fahnestock, George R. 1951. Correction of burning index for the effects of altitude, aspect, and time of day. U.S. Forest Serv. North. Rocky Mountain Forest and Range Expt. Sta. Res. Note 100, 15 pp. Gettinger, Henry, and Johnson, P. R. 1959. *The Gettinger burns. U.S. Dept. Agr., ASC office, College, Alaska, 8 pp. Hardy, Charles E., and Brackebusch, Arthur P. 1959. The Intermountain fire-danger rating system. Soc. Amer. Foresters Proc. 1959: 133-137, illus. *Address requests for copies to the originating office. Ti Hardy, Charles E., Syverson, Charles E., and Dieterich, John H. 1955. Fire weather and fire danger station handbook. U.S. Forest Serv. Intermountain Forest and Range Expt. Sta. Misc. Pub. 3, 84 pp., illus. Hayes, G. Lloyd. 1941. Influence of altitude and aspect on daily variations in factors of forest-fire danger. U.S. Dept. Agr. Cir. 591,38) pp., illus: Heintzleman, B. Frank. 1936. Western range. Alaska. U.S. Senate Doc. 199, 74th Congress, pp. 581-598, illus. 1960. Alaska — modern pioneering. Jour. Forestry 58: 435-436. Helmers, A. E. 1960. Alaska forestry — a research frontier. Jour. Forestry 58: 465-471, illus. Hirsch, Stanley N. 1962. *Possible application of electronic devices to forest fire detection. U.S. Forest Serv. Inter- mountain Forest and Range Expt. Sta. Res. Note 91, 8 pp. Hopkins, David M., Karlstrom, Thor N. V., and others. 1955. Permafrost and ground water in Alaska. Geological Survey Prof. Paper 264-F., pp. 113-146, illus. Washington: U.S. Govt. Printing Office. Johnson, P. R. 1958. *The Bouton burn. U.S. Dept. Agr., ASC office, College, Alaska, 3 pp. 1959. *The Bushley burn. U.S. Dept. Agr., ASC office, College, Alaska, 3 pp. Kincer, J. B. 1941. Supplemental climatic notes for Alaska. Climate and man, p. 1214. 1248 pp., illus. U.S. Govt. Printing Office. Lutz, Harold J. 1956. Ecological effects of forest fires in the interior of Alaska. U.S. Dept. Agr. Tech. Bul. 1133, 121 pp:, illus: 1959. Aboriginal man and white man as historical causes of fires in the boreal forest, with partic- ular reference to Alaska. Yale Univ. School of Forestry Bul. 65. 49 pp. 1960. Fire as an ecological factor in the boreal forest of Alaska. Jour. Forestry 58: 454-460, illus. , and Caporaso, A. P. 1958. *Indicators of forest land classes in air-photo interpretation of the Alaskan Interior. U. S. Forest Serv. Alaska Forest Res. Center Sta. Paper 10, 31 pp., illus. Nelson, Urban C. 1960. The forest-wildlife resources of Alaska. Jour. Forestry 58: 461-464, illus. 98 Palmer, Lawrence J., and Rouse, Charles H. 1945. Study of the Alaska tundra with reference to its reactions to reindeer and other grazing U.S. Fish and Wildlife Serv. Res. Rpt. 10, 48 pp., illus. Pomeroy, Kenneth B. 1959. An AFA fire plan for Alaska. Amer. Forests 65 (9) 12-13, 55, illus. Reed, Richard J. 1956. *Miscellaneous studies of polar vortices. Wash. Univ. Dept. Met. and Climatol. Occas. Rpt. App. illus. 1958. *Synoptic studies in Arctic meteorology. Wash. Univ. Dept. Met. and Climatol. Occas. Rpt. 9, 64 pp., illus. 1959. *Arctic weather analysis and forecasting. Wash. Univ. Dept. Met. and Climatol. Occas. Rpt. pat sop., illus: Rhode, Clarence J., and Barker, Will. 1953. Alaska's fish and wildlife. U.S. Fish and Wildlife Serv. Cir. 17, 60 pp., illus. Robinson, R. R. 1960. Forest and range fire control in Alaska. Jour. Forestry 58: 448-453, illus. Rowe, J. S. 1959: Forest regions of Canada. Canada, Dept. North. Affairs and Natl. Res. Forestry Branch Bul. 123, 71 pp., illus. Ottawa: The Queens Printer and Controller of Stationery. Stromdahl, Ingvar. 1956. *Statens brandinspektions verksamhet. The Govt. Insp. Fire Serv. Inform. Recommendations 1956: 13, 68 pp., Stockholm, Sweden. (In Swedish. Eng. summary, p. 68.) 1959. *Rikssbogsbrandstatistiken 1958 och en tillbakablick pa dren 1944-1958. Natl. Insp. Fire Serv. Inform. Recommendations 1959: 11, 12 pp., Stockholm, Sweden. (In Swedish. Eng. summary, pp. 11-12.) Swager, W. L., Fetterman, L. G., and Jenkins, F. M. 1958. A study of the cooperative forest-fire-control problem. Battelle Memorial Institute summary report to U.S. Forest Serv. 16 pp., illus. Columbus 1, Ohio. Taylor, Raymond F. 1956. A world geography of forest resources. Ch. 6. Alaska, pp. 115-125, illus. New York: Ronald Press Co. Uggla, Evald. 1958a. Ecological effects of fire on north Swedish forest. Uppsala Univ. Inst. Plant ecology, 18 pp., illus. Uppsala: Almqvist and Wiksells Boktryckeri AB. 1958b. Skogsbrandfalt i Muddus National Park. Uppsala Univ. Acta Phytogeogr. Suec. 41, 109 pp., illus. Uppsala: Almqvist and Wiksells Boktryckeri AB. (In Swedish. Eng. summary, pp..99- 109.) 99 U.S. Department of the Interior. 1945. Alaska. USDI Division of Territories and Island Possessions, 65 pp., illus. U.S. Forest Service. 1958. Timber resources for America's future. Separate |. A summary of the timber resources. U.S. Dept. Agr., Forest Serv. Forest Resource Rpt. 14, 109 pp., illus. U.S. Weather Bureau, Climate and Crop Weather Division. 1943. Climatic atlas for Alaska. U.S. Weather Inform. Branch Hdars. A.A.F. Rpt. 444, 229 pp., illus. Watson, C. E. 1959. Climates of the states — Alaska. USWB Climatography of the United States 60-49, 24 pp., illus. Zumwalt, Eugene V. 1960. The Alaska public domain. Jour. Forestry 58: 443-447, illus. 100 APPENDIX Division Tables Climatological Statistics —.......0000000... 18-33 Pure statistics, 200) .22).. ee Mees ee 34-43 Damage Statistics... 2 shee 44-46 Fire Control Statistics -...............0..00.0..... 47-55 101 Per Table 18.--Monthly and annual normal precipitation Aree niu a Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Interior Basin | Bettles 0.73 0.39 0.88 0.37 1.05 28 alae 3.09 2.25 1.44 0.69 01.57 Big Delta 58 a6 4 .28 64 2.31 2.99 1.98 1.43 200) 29 Pxets) Fairbanks 99 Avil uDd8 29 74 Teor. 1.92 2.26 dae 92 63 00 Fort Yukon 08 04 .28 ait, 32 awa 96 L628 OL BO 41 AER} Galena af alt 81 74 oli 63 1.69 2.69 2.84 2.4 .6 .6 6 Lake Minchumina 2/ McGrath 1.14 ES 98 49 94 2.06 2.52 3.63 2.41 1.67 109: 25 Northway «62 04 22 00 (2 2.00 2.89 ale He akenls} 49 06 Ol Summit aRs(eay 1.33 1.32 54 .98 QO 3.38 3.37 3.35 1.89 1.43 ast) Tanana 81 59 .58 26 ne) L.268 2.39 A509. 2995 05 .63 SO Arctic Drainage Kotzebue 47 32 Beat A 06 00 49 ARR ten) 195 94 358 43 OO West Central Bethel .90 .82 .92 755 .89 1320 2.29 4.02 S201) Us75 97 .85 Unalakleet 2/ Cook Inlet Anchorage .76 58 . 60 .40 BOIL .89 255 2.56 lei Ala esti 1.00 84 Homer 2.59 1.40 1.64 1.535 1:00 OY 1.66 2.89 2.79 3.74 2/55 2.76 Bristol Bay Tliamna 1.20 290) 1.33 TOI, 35 1.54 Naknek 94 1.24 ak sate) 280 228 oe. -80 5.03 3.99 3.20 1.50 1.88 -l10 4.14 3.49 2.73 1.30 Ted GW Copper River Gulkana ate] 42 SOT nel -Al alee) Ane Oi 2.15 74 -66 a a) ay Data for Sept.-Dec. not given in climatological summary, but obtained through correspondence. 2/ Not sufficient records to establish a mean precipitation. Source: U. S. Weather Bureau, Climatological Data, Annual Summary, 1958. 103 Table 19.--Percent of normal annual precipitation for the period March through August nee Month Total precipitation March April May June July Aug. March - August Annual Interior Basin Percent Inches Inches Bettles 6.3 Za0) Wleo 8.4 9.8 22 zal Siaul 7.94 14.01 Big Delta Pres) 2.4 5.5 19.59 PAT TO, 13.4 8.54 163 Fairbanks 4.9 224 6x2 ANS) Gia! 19.0 60.1 fikG Ib, 82 Ft. Yukon 4.3 256 459 TORS 14.8 OG heal 6.72 6.52 Galena bral 136 - 4.5 qa 6 18.6 TOIE5 60.4 5 1H 14.52 Lake Minchumina No record McGrath Byeak Pee CUB, HORS ee ale LOO 654.5 10.42 19.13 Northway aL a) Bele —S\c.6) 17.6 PO o(5} 16.0 TOMS Mass) 11.34 Summit 59 2.4 4.5 9.6 1b) 3 aE yee BAS Te Ae 2 22.25 Tanana 4.2 AGS) Sig) Oe 17.4 21.0 59/50 Srl USS TS) Arctic Drainage Kotzebue 3.3 AnD 245i. Saal Ke) 52 24.3 Gl 4.93 8.02 West Central Bethel Dye! 3.0 4.9 Gab 126 PPM 54.2 9.85 ilge}s IL7/ Unalakleet No record Cook Inlet Anchorage 4.2 2.8" OiaG 6.2 AOS) fp) 45.6 Gaol! UARAT Homer 6.5 52.0) 4:0 4.2 6.6 11.4 38.0 9.59 eORee Bristol Bay Tliamna De 5.9) sone 6.0 LORY AE) 50-7 25306 25.78 Naknek 52 SOU D6 6.6 Aor 18.0 Eats) ALEXA 05} Pe ( Copper River Gulkana One PAGu 2.10 HOW 18.01! 16.0 Oifecull 5 dLy/ tal 740) a NE Source: United States Weather Bureau, Climatological Data, Annual Summary, 1958. 104 Table 20.--Departure from 9-year average precipitation by number of days per month in each intensity class ANCHORAGE. Precipitation in hundredths of an inch o1- 10- 26- 50- 1.00- ie} Tr. 09 25 49 99 1.99 2.00+ April Total 20 9 1 [e) (e) Dep. from Av. ay 250: -2.7 -.9 ou -.1 May Total 16 12 3 0 [) [) Dep. from Av. ee ee -.4 -.6 -.3 -.1 June Total 12) 5 8 4 [) 1 Dep. from Av. -2.4 -1.9 2.9 ney} -.5 oT July Total 8 12 id 3 BE Dep. from Av. -4.6 5.7 9 -.3 eden -.4 -.2 August Total 15 10 2 2 es [°) Dep. from Av. 4.0 3.9 -5.2 -1.5 0 -1.1 -.1 FAIRBANKS April Total 26 3 a (e) Dep. from Av. 4.3 -2.7 -1.4 -.2 Mey Total 16 § 2! (0) Dep. from Av. -1.1 -.1 8 9 -.4 -.1 June Total 15 7 [e) (0) at [) Dep. from Av. 2rover 2 Lea, -2.3 oa ey -8 -.2 July Total 13 2 10 3 ee 1 (°) Dep. from Av. -1.1 -4.2 4.0 4 1.0 ie} -1 August Total 17 5 5 3 1 0 Dep. from Av. 5.9 -2.5 -3.2 -.4 ot -.4 -.1 GALENA April Total 19 6 2. 1 2 Dep. from Av. 1.2 -1.0 -2.5 5 1.8 May Total 19 10 2 (0) (0) (0) Dep. from Av. 4.3 2 -2.5 -1.6 -.3 -.1 June Totel 11 7 8 3 (e) 1 Dep. from Av. -3.7 2.2 alfa -.4 6: mae July Total 12 10 5 2 2 (0) Dep. from Av. -1.0 3.6 -1.3 -1.1 4 -.6 August Total 10 6 5 5 5 ie} Dep. from Av. 156% =78 2.1 -1.0 3.8 -1.5 HOMER April Total 16 6 4 [e) 3 [e) 1 Dep. from Av. 1.8 -.9 -1.4 -2.3 2.1 -.2 rh Mey Total 13 SEE 5 2 ie) 0 Dep. from Av. -1.3 2.3 -1.0 46 -.5 -.2 June Total 13 5 4 a (0) Dep. from Av. -2.1 -.4 1 1.8 rH f <1 July Total 10 9 10 1 z Dep. from Av. -6.6 5.0 4.4 -2.4 ie) 4 August Total 18 4 3 4 10) 0 Dep. from Av. 4.0 +3 -3.0 8 -.4 -1.5 -.2 NORTHWAY April Total 23 6 at [e) [e) Dep. from Av. 3.0 -.7 =1.9 -.2 ne May Totel ahh 8 9 3 ie} 10) Dep. from Av. -4.9 9 4.5 6 -.9 -~.2 June Total 16 uf 4 3 [e) Dep. from Av. 4.2) =06 -1.8 1 -1.0 -.8 July Total 1 8 6 5 3 2 Dep. from Av. -4,.8 1.4 -1.0 1.4 tbe / -.3 2.6 August Total 16 8 6 1 [e) (e) Dep. from Av. 4,3 ied -1.8 -1.7 -1.4 eta 1950 BIG DELTA Precipitation in hundredths of an inch O1- 10- 26- 50- 1.00- ie} “vat 09 25 49 99 1599) 2,.00+ April Total 25 2 3 [°) Dep. from Av. 3.8 -3.4 -.2 -.2 May Total att 1 5 cl 1 (o) Dep. from Av. -2.8 1.5 1.5 -.4 5 2 -.1 June Total 20 2 6 1 se 0 fe) Dep. from Av. 5.3 -3.8 } Paley} -.2 -.6 4 July Total 14 4 A 2 at 3 [e) Dep. from Av. -.3 -1.5 4 3 -.8 2.0 -.1 August Total 16 4 4 4 1 2 Dep. from Av. 2.4 -2.0 -2.0 1.5 -1.1 2 FT. YUKON April Total 25 2 3 te) (o) Dep. from Av. 129 25: BE -.4 - May Total 20 6 5 (e) (e) Dep. from Av. -2.8 8 2.6: -.4 - June Total 25 1 4 (e) (0) le) Dep. from Av. 4.8 -2.6 --7 -1.0 - -.2 July Total 23 5 3 (o) (o) Dep. from Av. 2.0 7 EN! yeedienk kaa August Total 20 9 1 (e) 1 Dep. from Av. 2.5 3.4 -3.9 -1.6 c Epa GULKANA April Total QT 2 1 (0) Dep. from Av. 4.6 -2.2 -1.6 -.8 May Total 17 «14 (°) (°) [e) Dep. from Av. -2.3 6.6 -3.5 -.5 - June Total 16 ue 2 5 [e) (0) Dep. from Av. -.2 1.8 -3.1 2.2 -.2 July Total 14 3 8 3 3 (°) Dep. from Av. 1.5 2 6 3 z -.8 -.1 August Total 19 v 3 BF 1 [o) Dep. from Av. 5.6 2,0 -4,8 -1.9 - -.0 McGRATH April Totell/ 19 5 2 3 [0 [e) Dep. from Av. 7 -1.3 -1.9 30) - -.2 May Total altg Tt 5 2 0 (0) Dep. from Av. 1.9 -1.7 a4 3 - -.2 June Total 9 2 6 2 Dep. from Av. -1.0 6 -3,9 2.8 1.4 -.4 nig July Total 9 8 4 4 6 [e) (o) Dep. from Av. =2.0° 1.9 -3.0 2) 3.4 -.6 -.2 August Total 10 3 9 3 4 2 [e) Dep. from Av. 2.4 -1.3 3 -2.8 ee 3 -.1 See footnote at end of table. 105 Table 20.--Departure from 9-year average precipitation by number of deys per month in each intensity cless--Continued 1953 EEE EEE ANCHORAGE: Precipitation in hundredths of an inoh o1- 10- 26- 50- 1.00- i) oy og 25 49 EE 1.99 2.00+ April Total 1606#ll 2 1 [*) [*) Dep. from Av. -2.2 4.0 -1.7 od -.1 -.1 Mey Total 15 bE 2 2 af 0 Dep. from Av. -.8 ae -1.4 1.4 at -.1 June Total 17 6 3 (e) (e) Dep. from Av. 2-62. -.9 -1.1 2 -.5 -.3 July Total 15 8 5 1 2 (o) ) Dep. from Av. CY a bey -1.1 -2.3 -.1 -.4 -.2 August Total 8 3 7 5 5 3 0 Dep. from Av. -3.0 -3.1 -.2 1.5 3.0 1.9 -.1 FAIRBANKS April Total 24 5 1 fe) Dep. from Av. 220) =e me -.2 May Total 15 6 3) [e) ak (e) Dep. from Av. -2.1 -2.1 4.8 -1.1 6 -.1 June Total 11 a2 3 2 1 [°) 1 Dep. fron Av. -1.5 3.8 2.5 -.3 -.1 -.2 8 July Total 17 4 4 5 ak (e) (+) Dep. from Av. 2.9 -2.2 -2.0 2.4 i) -1.0 -.1 August Totel 8 9 9: 3 1 ) ae Dep. from Av. -3.1 1.5 8 -.4 one -.4 9 GALENA April Total 17 #10 3 {+} fe) Dep. from Av. -.8 3.0 1.5 -.5 -.2 Mey Total 12 ll & 3 (e) 1 Dep. from Av. -2.7 1.2 -.5 1.4 -.3 oe) June Total 12 8 5 3 i fe) it Dep. from Av. -2.7 1.3 -.8 LoL -6 -.4 9 July Total 18 6 5 1 1 0 Dep. from Av. 5.0 -.4 -1.3 -2.1 6 -.6 August Total 2 abe 8 5 z 4 Dep. from Av. -6.4 4.2 oi) -1.0 -.2 2.5 June Total 17 8 3 (e) 2 fe) Dep. from Av pet em Ef) -1.9 -2.2 wil, 1 July Total 23 5 2 aE (o) () Dep. from Av 6.4 1.0 -3.6 -2.4 -1.0 -.4 August Total 12 3 4 4 3 Dep. from Av. -2.0 -.7 -1.0 -8 1.6 15. -.2 NORTHWAY April Totell/ 9 ? 3 Dep. from Av 1.0 3 nL See footnote at end of table. 106 BIG DELTA Precipitation in hundredths of an inch O1- 10- 26- 50- 12.00- o Tr. 09 25 49 EE 2.99 2.00+ April Totel 22 { 1 (e) Dep. from Av. -8 2.6 =-2.2 -.2 ee 2 Totel 12 6 9 1 1 [) Dep. from Av. -7.8 .5 5.5 -6 a) 8 -.2 June Total 14 3 7 3 2 [s) 1 Dep. from Av. -.7 -2.8 aS) 8 8 -.6 6 July Total 16 4 7 1 2 zi [e) Dep. from Av. Wot. 15. 4 -.7 a ie) -.1 August Total 10 7 9 1 4 [e) Dep. from Av. -3.6 1.0 3.0 -1.5 19 -.8 FI. YUKON April Total 28 1 1 te) ) Dep. from Av. 4.9 -2.5 -1.9 =c4 5 =e! : May Total 26 4 1 () [) Dep. from Av. 3.2 -1.2 -1.4 -.4 -.2 = June Total 21 2 4 2 1 Dep. from Av. -8 -1.6 -.7 1.0 BY f -.2 July Total 20 i 9 L [e) Dep. from Av -1.0 -3.3 5.3 -.7 -.3 August Totel 19 5 4 1 2 [*) Dep. from Av. 1.5 -.6 -.9 -.6 one -.1 GULXANA April Total 24 3 2 1 Dep. from Av. 1.6 -1.2 -.6 2c May Total 18 9 4 (e) [e) Dep. from Av. -1.3 1.6 oh) -.5 -.3 June Total 14 5 8 3 fe) Dep. from Av -2.2 -.2 2.9 2 5 -.2 July Total 17 6 2 5 1 () [e) Dep. from Av. DES se jock -5.4 2.2 meh -.8 -.1 Augus? Total 8 at ThE 2 2 1 Dep. from Av. -5.4 2.0 3.2 -.9 if 4 McGRATH April Total 18 6 5 i () Dep. from Av --3 -.3 Leb -.1 -.2 -.2 May Totel 7 14 4 al 1 Dep. from Av. -8.1 5.3 -.8 2.3 5 8 June Total i 8 z 1 te) Dep. from Av. -2.0 1.4 2% -2.2 -.6 6 -.3 Total 16 5 6 1 fe) fe) Dep. from Av. 4.3 -1.1 -1.0 -2 -1.6 -.6 -.2 August Totel 4 3 12 5 2 5 fe) Dep. from Av. -3.6 -1.3 3.3 -.8 -.8 3.3 -.1 Table 20.--Departure from 9-year average recipitation by number of days per month in each intensit. olass~-Continued ANCHORAGE: Preoipitation in hundredths of an inoh ol 10- 26- 50- 1.00- ie) Tr. 09 25 49 99 1.99 2.00+ April Total 25 4 aL 1°} ie} Dep. from Av. 6.8 -3.0 -2.7 =i9) -.1 -.1 May Total Leo 4 [e) (0) [e) Dep. from Av. Lee) =. 8: .6 -.6 -.3 = June Total 15 9 2 3 1 Dep. from Av. acy Ak -3,1 ne 5 July Total 12 6 7 3 3 (0) [°) Dep. from Av. -.6 -.3 at) -.3 9 -.4 -.2 August Total 12 6 6 4 2 1 [°) Dep. from Av. 1.0 -.1 -1.2 “5 0 -.1 ph FAIRBANKS April Total 22 8 [¢) (0) Dep. from Av. 1d “2.95 -2.4 -.2 May Total 24 4 2 1 [e) Dep. from Av. 6.9 -4,1 -2.2 -.1 -.4 -1 June Total 14 8 2 3 3 (e) [e) Dep. from Av. POM =e. -3.5 Ate anet:) -.2 -.2 July Total 13 6 4 5 a 1 1 Dep. from Av. -l.1 -.2 -2.0 2.4 0 0 19 August Total 9 10. 9: 3 [e) [e) Dep. from Av. -2.1 2.5 8 -.4 -.3 -.4 -.1 GALENA April Total 23 4 2 ah [e) Dep. from Av. §.2 -3.0 2.5 =o: -.2 May Total al it 3 (0) (o) () Dep. from Av. 6.3 -2.8 -1.5 -1.6 -.3 -.1 June Total 21 2 4 2 al (0) 0 Dep. from Av. 6.3 -4.7 -1.8 el +6 -.4 -.1 July Total 10 10 3 3 4 1 Dep. from Av. 3.0 3.6 -3.3 -.1 2.4 4 August Total 8 ¥e 6 9 BE (e) Dep. from Av. -.4 .2 -1.1 3.0 -.2 =1.5 HOMER . April Total 23 6 1 [e) [e) () [e) Dep. from Av. 8.8 -.9 -4.4 -2.3 -.9 -.2 -.1 May Total 15 9 5 2 (o) 0 Dep. from Av. orl, ¥O. -1.0 ait =.9 -.2 June Total 18 10 1 1 (e) ie} Dep. from Av. 2.9 3.6 -3.9 -1.2 -1.3 --1 July Total 17 3 5 5 ak Dep. from Av. +4 -1.0 -.6 1.6 ie} -.4 August Total 14 3 4 3 3 4 Dep. from Av. 10} -.7 -2.0 -.2 6 2.5 2 NORTHWAY April Total 18 9 3 (6) [s) Dep. from Av. -2.0 2.3 ee -.2 ~.2 May Total 19 We a to) 3 a Dep. from Av. 3.1 -.1 -3.5 -2.4 cyt 8 June Total ye 9, 8 4 1 Z Dep. from Av. -4.9 1.4 22 plea} 0 AS July Total fae eal 10 2 1 o) Dep. from Av. -4.8 4.4 3.0 -1.6 -.3 -.3 -.4 Total ay g 6 6 (e) Dep. from Av. 5.3 -1.3 -1.8 ie} Sl! 1954 BIG DELTA Preoipitation in hundredths of an inch ol 10- 26- 50- 1.00- 0 Tre 09 25 49 99 1.99 2.00+ April Total 19 Hf 4 (e) Dep. from Av. -2.2 1.6 8 -.2 May Total ay 4 2 3 ak (e) ie) Dep. from Av. 1.2 -1.5 -1.5 1.6 a] -.2 =a June Total 13 8 4 1 2 1 1 Dep. from Av. -1.7 2.2 -1.1 -1.2 A) 4 +6 July Total 12 5 10 ay 2 eT (o) Dep. from Av. -2.3 -.5 3.4 -.7 :2 (0) =k August Total 16 at 3 3 2 [e) Dep. from Av. 2.4 1,0 -3.0 5 =a -.8 FT. YUKON April Total 27 2 1 i) (o) Dep. from Av. 3.9 -1.5 mie -.4 -.1 May Total 28 1 2 [e) [o) Dep. from Av. 5.2 -4.2 -.4 4 -.2 June Total Lv, 4 8 1 [e) [e) Dep. from Av. -3.2 4 3.3 0 -.3 -.2 July Total 15 6 3 6 1 Dep. from Av. -6.0 1.7 -.7 4.3 eH e August Total 17’ 3 9 [°) 2 [e) Dep. from Av. -.5 -2.6 4.1 -1.6 if Phe GULKANA April Total 30 (0) (0) (e) Dep. from Av. 7.6 -4.2 -2.6 -.8 May Total 19 6 5 (e) al Dep. from Av. -.3 -1.4 1.5 -.5 7 June Total 18 4 5 a 1 () Dep. from Av. 1.8 -1.2 ae -.8 5 2 July Total 14 2 10 1 4 (0) 0 Dep. from Av. -1.5 -.9 2.6 -1.8 230) -.8 -.1 August Total 16 3 7 4 tt (°) Dep. from Av. 2.6 -2.0 -.8 pepal, -.3 -.6 McGRATH April Total 20 6 3 a (e) [) Dep. from Av. a Rey Geri) -.9 -.1 mies -.2 May Total 26 1 3 7 [o) [°) Dep. from Av. 10.9 -7.7 -1.8 EPH 6 -.5 -.2 June Total 2 9 2 5 5 ar (e) Dep. from Av. 2.0 -.6 -3.9 1.8 4 6 -.3 July Total 10 8 6 [e) 4 3 (e) Dep. from Av. -1.7 1.9 -1.0 -2.8 1.4 2.4 -.2 August Total ay 4 7 3 5 1 [e) Dep. from Av. 3.4 -.3 Sete -2.8 2.2 -.7 =e See footnote at end of table. 107 Table 20.--Deperture from 9-year average precipitation by number of deys per month in each intensity cless--Continued ANCHORAGE Precipitation in hundredths of an inch o1- 10- 26- 50- 1.00- ire og 25 49 99 99 2.00+ Mey. Total 23 id 1 (e) Dep. from Av. 7.2 -3.8 -2.4 -.6 -.3 cat June Total 23 2 2 3 0 Dep. from Av. 8.6 -4.9 -3.1 or 5 3 July Totel 16 3 5 6 1 Dep. from Av. 3.4 -3.3 -1.1 2.7 -1.1 --4 .2 August Total 16 2 8 3 a! uf (e) Dep. from Av. 5.0 -4.1 -8 ==9 -1.0 -.1 Seal FAIRBANKS April Total a1 a 5 (e) Dep. from Av. --7 -1.7 2.6 -.2 May Total 19 8 4 (0) 0) 0 Dep. from Av. L.9 --.2 -.2 -1.1 -.4 -.1 June Total 20 5 5 [o) [e) (e) ie) Dep. from Av. 7.5 -3.2 5 -2.3 -1.1 2 me July Total 14 12 4 1 (e) [e) 0 Dep. from Av. -.1 5.8 -2.0 -1.6 -1.0 -1.0 -.1 August Total 16 6 8 at, [e) fe) Dep. from Av. 4.9 -1.5 -.2 -2.4 -.3 4 -.1 GALENA April Total 20 5 5 [*) [°) Dep. from Av. 2.2 -2.0 “B) -.5 -.2 May Total 20 5 2 3 i Dep. from Av. 5.3 -4.8 2.5 1.4 7 al June Total 25 2 3 (e) i) 0 (e) Dep. from Av. 10.3 -4.7 -2.8 ag, -.4 -.4 -.1 July TotalL/ 19 5 4 2 5 ie) Dep. from Av. 6.0 -1.4 -2.35 -1.1 1.4 6 August Total 10 af 6 ) ul Dep. from Av. 1.6 ee el 1.0) -1.2 -.5 HOMER April Totel aby 7 2 3 1 0 Dep. from Av. 2.8 out -3.4 aide 1 -.2 ml Mey Total 19 8 2 2 Ce) ) Dep. from Av. 457 net 4.0: anf -.5 -.2 June Total 26 2 FS (e) [o) Dep. from Av. 10.9 -4.4 -2.9 -2.2 -1.3 at July Total 17. ) 6 6 1 1 Dep. from Av. 4 -4.0 4 2.6 0 6 Total 19 1 5 (e) 5 0 al Dep. from Av. 5.0 -2.7 -1.0 -3.2 2.6 -1.5 8 NORTHWAY April Total 17 8 & zh ) Dep. from Av. -3.0 1.35 Pe 8 -.2 Mey Total 15 5 ff 3 1 (e) Dep. from Av. -.9 -2.1 2.5 -6 1 2 June Total 12 5 6 3 3 1 Dep. from Av 1 -2.6 2 aL 2.0 2 July Total 14 3 9 i 3 af () Dep. from Av 2.2 -3.6 2.0 -2.6 1.7 7 -.4 August Totel Data missing 1957 Precipitation in hundredths of en inch O1- 10- 26- 50- 2.00- i} Tr. og 25 49 39 2.99 2.00+ April Total 19 5 6 (+) Dep. from Av. -2.2 4 2.8 -.2 Total 23 6 2 fo) (+) Q Dep. from Av. 3.2 5 -1.5 -1.4 -.5 -.2 -.1 June Total 18 6 2 3 z [e) (e) Dep. from Av. 3.3 ae) -3.1 8 -.2 -.6 -.4 July Total 16 4 1h 1 2 z (+) Dep. from Av. 1.7 -1.5 4 -.7 > ie) =. August Total 18 4 1 2 af Dep. from Av. 4. -2.0 -1.5 -.1 2 April Totel 26 3 Q 1 (+) Dep. fron Av 2.9. =-.5 -2.9 6 --1 Mey Total 2s 5 2 1 Dep. from Av. BC se: 4 6 a June Total 23 5 fe) () ie) Dep. from Av. 2.8 -1.6 -3 -1.0 a) -.2 July Totel 7 2 1 Dep. from Av Carte -1.7 -.7 -.3 August Total 22 6 (e) i (e) Dep. from Av. 4.5 4 -2.9 -1.6 -.3 -.1 GULKANA April Total 22 4 4 (e) Dep. fron Av. -.4 -.2 1.4 -.8 May Total 18 8 4 1 Dep. from Av. -1.3 -6 -5 ee] 3 June Total 16 4 5 Q Dep. from Av. --2 -1.2 -.1 2.2 -.5 -.2 July Totel 17 1 io) 4 2 1 0 Dep. from Av. 1.5 -1.9 1.4 rhe -5 a -.1 August Total 22 3 3 3 () (e) Dep. from Av. 8.6 -2.0 -4.8 aul -1.3 -.6 McGRATH April Total 21 4 5 ° 0 () Dep. from Av. 2.7 -2.3 meat -1.1 Lane -.2 Total 19 5 4 2 2 [°) Dep. from Av. 3.9 -3.7 -.8 5 25) -.2 June Total 19 6 3 2 [°} (e) Dep. from Av. 9.0 -3.6 -2.9 -1.2 6 -.4 -.3 July Total 1¢ 8 6 3 () [e) fe) Dep. from Av. 2.3 1.9 -1.0 2 -2.6 -.6 -.2 Augus® Total ‘70 8 6 ie) ie) ie) Dep. from Av. -.6 5.7 -.7 “2 -2.8 -1. See footnote at end of teble. 108. Table 20.--Departure from 9-year average precipitation by number of days per month in each intensity class--Continued 1958 ANCHORAGE Precipitation in hundredths of an inch O1- 10- 26- 50- 1.00- 1°) irs 09 25 49 99 1,99 2.004 April Total 22 3 4 a 0 Dep. from Av. 3.8 -4.0 3 oll ou -.1 May Total ne 8 7 3 1 Dep. from Av. -3.8 -2.8 3.6 2.4 He =.1 June Total 15 4 iG 2 2 Dep. from Av. 6 -2.9 1.9 -.8 =25) Lot July Total 8 9 2 3 2 1 Dep. from Av. -4.6 -.3 a9; -1.3 ae 1.6 8 August Total 12 5 ai () [e) Dep. from Av. 1.0 -.1 -.2 1.5 -1.0 Eales -.1 FAIRBANKS a April Total al 7 2 (0) Dep. from Av. mille dso: -.4 -.2 May Total 18 9 2 1 ae Dep. from Av. 9 9 -2.2 -.1 6 -.1 June Total ll 10 4 3 2 {0} Dep. from Av. -i.5 1.8 -1.5 7 cI -.2 -.2 July Total 13 10 5 al nb a6 0) Dep. from Av. -l.1 3.8 -1.0 -1.6 ie} 0 a August Total 9 12 8 2 () fe) Dep. from Av. -2.1 4.5 -.2 -1.4 -.3 -.4 ay GALENA April Total 19 6 5 [s) [o) Dep. from Av. 1.2 -1.0 -5 -.5 -.2 May Total 12 rat 6 2 Dep. from Av. -2.7 1.2 1.5 4 -.3 -.1 June Total 9 4 12 3 BE a 0 Dep. from Av. -5.7 -2.7 6.2 Y.1 6 6 =e July Total Data missing Dep. from Av. August Total Data missing Dep. from Av. HOMER April Total LT 4 4 5 (0) ie) Dep. from Av. 2.8 -2.9 —1.4 2.7 -.9 -.2 and May Total 8 8 12 2 al Dep. from Av. -6.3 -.7 6.0 w6 5 -.2 June Total ah 9 4 5 i) Dep. from Av. -4.1 2.6 -.9 2.8 -.3 -.1 July Total 14 3 6 5 2 a Dep. from Av. -2.6 -1.0 A 1.6 1.0: 6 August Total 12 4 8 5 ie} 2 1°} Dep. from Av. -2.0 3 2.0 1.8 -2.4 5 -.2 NORTHWAY April Total 26 2 ay (e) aT, Dep. from Av. 6.0 -4.7 Abr} -.2 8 May Total 16 T 4 3 a Dep. from Av. at S. -.5 -6 1 -.2 June Total 23 1 4 J [e) Dep. from Av. 11.1 -6.6 -1.8 -.9 -1.0 -.8 July Total 13 9 ak 1 1 Dep. from Av. 1.2 6 2.0 -2.6 -.3 rt -.4 August Total 14 6 5 2 3 1 Dep. from Av. 2.3 -1.3 -2.8 -.7 1.6 9 1/ Discrepancy BIG DELTA Precipitation in hundredths of an inch O1- 10- 26- 50- 1.00- 0 Tr. o9 25 49 99 17.99: 2,00+ April Total 24 5 1 0 Dep. from Av. 2.8 -.4 -2.2 -.2 May Total 23 a a 0 0 0 Dep. from Av. Sead -2.5 -1.4 -.5 -.2 a. June Total Ey, 6 5 if 1 () (e) Dep. from Av. 2.3 4 -.1 -1.2 -.2 -.6 -.4 July Total 15 11 2 2 0 a [e) Dep. from Av. wii, 9 Die'0! -4.6 3 -1.8 0 =i August Total 15 Td 2 2 0 x Dep. from Av. L4 5,0 -4.0 -.5 -2.1 2 FT. YUKON April Total 20 7 2 x 0 Dep. from Av. -3.1 3.5 -.9 6 -.1 Mey Total al 6 3 1 Dep. from Av. -1.8 8 a6 6 -.2 June Total 22 2 4 2 Dep. from Av. 1.8 -1.6 -.7 1.0 -.3 -.2 July Total al 6 1 2 ab Dep. from Av. ce) 1.7 -2.7 13 ot August Total 18 6 3 2 2 Dep. from Av. aa 14 -1.9 A at: -.1 GULKANA wipril Total ne} 10 1 () Dep. from Av. -3.4 5.8 -1.6 -.8 May Total 13 13 3 2 () Dep. from Av. -6.3 5.6 -.5 1.5) -.3 June Total 22 4 3 ph 0 Dep. from Av. 5.8 -1.2 -2.1 -1.8 5 -.2 July Total 14 4 8 3 1 a Dep. from Av. -1.5 1.1 6 2 -.5 2 1 August Total Le 4 T 2 3 a Dep. from Av. -6 -1.0 -.8 -.9 eT 4 McGRATH April Total 20 8 1 (0) at [e) Dep. from Av. 1.7 1:7 -2:9 <-1.2 28 -.2 May Total 12 10 8 ai [e) Dep. from Av. -3.1 1.3 3.2 -.7 -.5 -.2 June Total 6 9 10 5 (e) (e) Dep. from Av. -4,0 -.6 4.1 1.8 -.6 -.4 -.3 July Total 8 6 10 5 (e) 2 i) Dep. from Av. -3.7 Ay 3.0 2.2 -2.6 1.4 2 Total 6 2 12 6 4 mn, te) Dep. from Av. -1.6 -2.3 3.3 2 1.2 -.7 -.1 in basic data. 109 Teble 21. --Monthly precipitation and departure from normal Avon January February March April May June July August September October November December Total De Ant _De Amt De Amt Dep Amt De Amt De Interior Basin Big Delta 1.13 -64 .06 -.15 .69 -44 .07 -.28 .71 -00 .61 -1.82 3.37 -21 2.27 241 +43 -.88 -69 -29 .53 Fairbanks 2.00 : . . . : -86 -.56 2.50 -60 1.17 -1.00 -51 -.95 -51 -.36 .99 Fort Yukon -68 +26 .06 -.35 .27 -.05 .07 -.19 .13 -.32 .07 -.73 .06 -.94 -32 -.91 -62 -.09 -50 -.14 .48 -.-78 7.03 -1.17 -1.85 5.08 -1.50 -3.10 -65 -2.79 w v iv) i) oO 1 nm oO on i) ' ry > ° a ' ie) @ o i) 1 w o Galena deh -63 .12 -.63 .18 -.63 .80 -66 .12 -1.33 1.88 -64 1.07 -1.60 2.58 -.25 1.87 31 -26 -.36 .33 -2.33 6.45 -1.58 McGrath 1.80 .68 .07 -1.23 .03 -1.11 .67 .28 .52 -.51 4.36 2.44 2.84 .46 2.82 -.76 2.13 -.29 .44 -1.42 .51 -2.40 11.21 1.77 Northway -98 .38 .04 -.38 .11 -.15 .03 -.37 .99 .30 .58 -1.42 4.83 1.94 .39 -1.83 .54 -.90 .23 -.31 .31 -2.72 6.82 -.95 Cook Inlet Anchorage -83 -.01 Tr -.67 .29 -.26 .04 -.37 .10 -.40 1.90 1.20 .97 -.66 .92 -1.68 1.07 -1.51 .52 -1.66 .26 -.78 1.71 .86 8.61 -5.94 3.93 -1.98 Homer -71 -1.98 .16 -1.41 1.08 -.77 2.75 1.48 .50 -.64 1.40 -38 1.02 -.74 1.34 -1.78 2.63 -2.84 2.36 -1.57 .08 -2.32 1.44 -1.37 15.47 -13.56 7.01 -.94 Copper River Gulkana -86 -.03 .39 -.04 Tr -.45 .06 -.37 Tr --47 .81 -.42 2.81 -70 53 -1.33 1.75 hy f 44 -.42 .87 -22 -73 -.23 9.25 -2.67 4.21 -1.59 Interior Basin Big Delta -04 -.34 .30 14 416 =-.18 .04 =-.24 1.81 1:17 2.67 362.05 -.94 1.77 -21 -63 -.80 -3L -.19 .03 -.26 -18 -.15 9.99 -1.64 8.34 -14 Fairbanks +12 -.87 .27 -.24 .20 -.38 .01 -.28 .64 -.10 1.85 -48.1.37 -.55 2.97 Aiph alee gibt -1l -.81 Tr -.63 -13° -.37 8.99 -2.93 6.84 -26 Fort Yukon -19 -.19 .22 -.12 .12 -.16 .01 -.16 .02 -.30 1.00 -29 .66 -.30 1.16 -.12 89 -06 -45 -.12 .20 -.21 -67 -38 5.59 -.93 2.85 -.59 Galena -10 -.67 1.03 722 .20 -.54 .11 -.07 1.38 -75 2.15 46 .69 -2.00 4.02 1.18 1.10 -1.27 -34 -.30 .21 -.43 -35 -.27 11.68 -2.94 8.35 -32 McGrath +27 -.87 .97 -.18 .18 -.80 .24 -.25 1.98 1.04 1.12 -.941.15 -1.17 5.86 2.23 1.86 -.55 .33 -1.34 .21 -.88 .61 -.64 14.78 -4.35 10.35 -91 Northway -07 -.54 .06 -.28 .12 -.10 .11 -.24 1.35 -63 4.00 2.00 1.24 -1.65 2.12 -31 -95 -.23 -41 -.08 .07 -.29 -24 -.13 10.74 -.60 8.82 1.05 Cook Inlet Anchorage -20 -.56 .48 -.10 .21 -.39 .15 -.25 .76 -25 .57 -.32 1.14 -.41 5.06 2.50 1.85 -.86 -81 -1.06 .11 -.89 1.11 -27 12.45 -1.82 7.68 1.77 Homer -98 -1.41 3.57 2.17 .21 -1.43 1.49 -16 2.04 1.04 .74 -.33 .16 -1.50 4.81 1.92 2.43 -.36 3.62 -08 2.74 -19 2.20 -.56 25.19 -.03 9.24 1.29 Copper River Gulkana -18 -.61 .62 20 «4.47 -10 .18 -.03 .18 -.23 .72 -.47 1.09 -1.03 2.08 -21 21.39 -.74 -Tl -.03 .15 -.51 -92 -13 8.69 -3.01 4.25 -1.55 1954 Interior Basin F Big Delta 48 -10 .05 -.11 .20 -.14 .13 -.15 1.15 -51 3.37 1.06 2.06 -.93 1.49 -.49 2.06 -63 -58 -.12 .19 -.10 -31 -.02 11.87 -24 .8.20 -00 Fairbanks -55 -.44 .21 -.30 .60 -.02 Tr -.29 .17 -.57 1.78 41 3.22 1.30 -84 -1.42 1.82 -61 708 -.84 .42 -.21 -48 -.02 10.17 -1.75 6.01 -.83 Fort Yukon -58 =20) 27,7 -=.0%) 1.28 -00 .0l -.16 .10 -.22 .41 -.30 1.26 -30 92 -.36 OHH teak -41 -.16 .84 43 -79 -50 6.64 -12 2.70 -.74 Galena -19 -.58 .18 -.63 .35 -.39 .23 -05 .09 -.54 .95 -.74 2.81 -12 1.79 -1.05 1.87 -.50 -41 -.25 1.45 -.19 -44 -.18 9.76 -4.86 5.87 -2.16 McGrath -63 -.51 .28 -.87 1.04 -06 .29 -.20 .34 -.60 1.83 -.23 4.73 2.41 5.22 -.41 3.59 1.18 -73 -.94 1.85 -76 1.43 -18 19.96 -83 10.41 -97 Northway -16 -.45 .15 -.19 .18 -.04 .14 -.21 1.52 -80 1.71 -.29 1.21 -1.68 -60 -1.21 -90 -.28 eel =.28 219° -.17; +51 14 7.48 -3.86 5.18 -2.59 Cook Inlet Anchorage -56 -.20 .18 -.40 .97 -37 .03 -.37 .15 -.36 .91 -02 2.08 53 2.13 -.43 1.66 -1.05 2.02 -15 .93 -.07 1.00 -16 12.62 -1.65 5.30 --61 Homer P.129=2.27 676: —.64° 1.93 -29' .O1 -1.32 .43 --.57 :26 -.81 1.90 -24 4.13 1.24 1.47 -1.32 4.63 -89 2.44 -.11 1.34 -1.42 20.42 -4.60 6.73 -1.22 Copper River Gulkana -33 -.46 .52 -10 .22 -.15 .00 -.21 .39 -.02 .69 -.50 1.94 -.18 1.48 -.39 1.75 -.38 -86 -12 .61 -.05 84 -05 9.63 -2.07 4.50 -1.30 1957 Interior Basin Big Delta 1.35 -97 1.33 1.17 .46 -12 .11 -.17 .03 -.61 1.05 -1.26 1.92 -1.07 1.65 -.33 -T2 -.71 -63 =1300 09) —-20 i. 06! -23 9.90 -1.73 4.76 -3.44 Fairbanks 192 +93 £56 -05 .15 -.43 .08 -.21 .07 -.67 .21 -1.16 .40 -1.52 -40 -1.86 -47 -.74 -7T4 -.18 .30 -.33 -25 -.25 5.55 -6.37 1.16 -5.68 Fort Yukon 56 -18 .38 704 .22 -.06 .13 -.04 .23 -.09 .22 -.49 .27 -.69 -38 -.90 -58 -.23 -45\.-.12) (.49 -08 -26 -.03 4.17 -2.35 1.23 -2.21 Gelena 1.10 -53 2.79 -.02 .49 -.25 .17 -.01 .73 -10 .18 -1.51 1.40 -1.29 2.14 -.70 1.76 -.61 1.00 -36 1.63 a «49 -.13 11.88 -2.74 4.62 -3.41 McGrath 3.67 2.53 1.11 -.04 .72 -.26 .19 -.30 .82 -.12 .42 -1.64 .79 -1.53 1.21 -2.42 2.17 -.24 1.43 -.24 1.53 44 -53 -.72 14.59 -4.54 3.43 6.01 Northway +43 -.18 .47 215.29 -O7 .43 -08 1.21 49 2.12 12 2.51 -.38 Missing data 23T -O1 43 -06 Cook Inlet = Anchorage 1.36 -60 .67 -09 .20 -.40 .01 -.39 .02 -.49 .56 -.33 1.64 -09 2.02 -.54 3.21 -50 +93 -.94 1.51 ol -56 -.48 12.49 -1.78 4.25 -1.66 Homer -94 -1.45 .83 -.57 .42 -1.22 .76 -.57 .37 -.63 .09 -.98 2.26 -60 3.04 -15 4.30 1.51 3.63 -.11 6.00 3.45 2.35 -.41 24.99 --23 6.52 -1.43 Copper River Gulkana -51 -.28 .49 .0O7 .09 -.28 .11 -.10 .42 -01 1.04 -.15 2.67 -55 -66 -1.21 3.41 1.28 1.56 362" 351 -=-15 41 -.38 11.88 -18 4.90 -.90 1958 Interior Basin Big Delta -38 -.03 .06 -.10 .36 -02 .0Ol -.27 .08 -.56 .79 -1.52 1.07 -1.92 -96 -1.02 -75 -.68 -90 -40 .44 15 -25 -.08 6.02 -5.61 2.91 -5.29 Fairbanks -31 -.68 .07 -.44 .24 -.34 .09 -.20 .57 -.171.01 -.36 1.42 -.50 -61 -1.65 46 -.75 -84 -.08 .40 -.23 -41 -.09 6.43 -5.49 3.70 -3.14 Fort Yukon -68 -30 .07 -.27 .26 -.02 .15 -.02 .17 -.15 .39 -.32 .82 -.14 .97 -.31 -22 -.59 1.22 -65 1.17 -76 34 -05 6.46 -.06 2.50 -.94 Galena -80 205 .21 -.60 .59 -.15 .11 -.07 .47 -.16 1.69 00 3.53 -84 2.46 -.38 Missing data 8.26 -23 McGrath -36 -.78 .18 -.97 .64 -.34 .32 -.17 .44 -.50 1.10 -.96 2.88 -56 3.73 -10 2.95 54 -81 -.86 .68 -.41 -17 -1.08 14.26 -4.87 8.47 -.97 Northwey -20 -.41 .18 -.16 .16 -.06 .43 -08 .76 -04 .51 -1.49 1.47 -1.42 2.94 1.13 1.07 -.11 1.05 -56 .32 -.04 +23 -.14 9.32 -2.02 6.11 -1.66 Cook Inlet Anchorage 1.05 229 07. -.52 219: =.42 <25 =.25 1.05 -54 2.19 1.30 4.44 2.89 1.67 -.89 1.351 -1.40 1.93 -06 1.41 41 +54 -.30 16.10 1.83 9.60 3.69 Homer 3.74 1.35 .48 -.92 1.69 -05 .86 -.45 1.12 -12 1.12 -05 2.48 -82 2.89 -00 2.37 -.42 2.08 -1.66 4.72 2.17 1.05 -1.71 24.62 -.60 8.49 -54 Copper River Gulkana 1.02 .23 .24 -.18 .33 -.04 .01 -.20 .33 -.08 .29 -.90 1.73 -.39 2.02 .15 1.10 -1.03 1.66 .92 .84 .18 .87 .08 10.44 -1.26 4.38 -1.42 SS EE Source: USWB Climatological Data, Alaska Annual Summary, for the years mentioned. 110 Table 22.--Precipitation intensity classes, according to frequency of occurrence by decades of the month 1950-58) (Av. BETHEL Time of ANCHORAGE Time Precipitation in hundredths of an inch Precipitation in hundredths of an inch 1,0- -50- +99 +26- .10- 225 April -O1- 09 1.0- 1.99 «50- eee) -26- .10- «25 April 0.1 -O1- of Month 2.0+ +49 Drs Month ie} 2.0+ 249 -09 Tr. 0 3.3 2.0 2.2 4.6 3,9 S.1 16 1-10 11-20 21-30 Total 0.1 2.0; 220 3.0 5,8 1-10 11-20 21-30 0.1 5.8 6.6 18.2 mil 2. 5.4 25 2.0 1.0 8225855 Total Ma. May =2 1-10 11-20 21-31 Total 1-10 528 126 13 11-20 21-31 0.1 ne 8.6 6.8 12.0 wl 15.8 10.8 3.4 6 Total June June +6 12 2.8 2.4 3.3 2,0 2.4 2.6 8.5 7.0 eye 3.0 3 1-10 11-20 21-30 Total ol el 2.7 1.35 5.4 4,4 4.6 14.4 1-10 11-20 21-30 Total 1.9 2.0 2.9) 1.8 8 9 9.6 July July 9 1-10 11-20 21-31 4.3 2.0 1.9 1-10 tral TAC} 2.1 4.2 625 G92 Bie) 260 O.1 11-20 4.1 2.3 1.8 4.2 2.0 2.4 12 21-31 Total 0.2 9.35 Total 6.3 6.1 6 August puso) August 1.0 2.3 3.6 alal 2.4 1-10 11-20 21-31 Total 1.7 2.4 3.7 1-10 ca lieey iia 11-20 21-31 Total 1.2 4.7 1.8 2.5 2.4 6eteTse 2.4 11.0 5.9 i417. 3.5 BIG DELTA Time of BETTLES Time of Precipitation in hundredths of an inch Precipitation in hundredths of an inch 1.0- 1.99 -10- -26- .50- «99 225 April .O1- 1.0- -50- 99 -10- .26- +25 April 0.3 .O1- 2.0+ +49 .09 Ta Month 0 2.0+ 1.99 49 209 Tre (e) Month 1.9 1.4 6.7 7.4 1-10 11-20 21-30 Total 0.1 2.8 1.3 5.4 6.8 1-10 11-20 21-30 Total enh alc snlal Lobe 0) 5.4 3.2 nee 21.2 Meals +2 6 6.6 3,3 19.3 Ma, 1-10 11-20 21-31 Total 6.9 1.4 1.2 4 1-10 onl el 7.9 11-20 21-31 a) 2.0 1.9 5.7 1958 A wale 8 3.8 1.3 7.6 3.6 5.2 18.4 Total June June 8 “6 1.9 1.2 1.6 2.0 210, 250: 6.8 1-10 11-20 21-30 1.3 1.0 3.2 1.1 6.8 1-10 11-20 21-30 Total 4.2 O.1 4.4 3.7 el 16.0 July +3 1-10 11-20 21-31 July _ Hf 1-10 11-20 21-31 Total 1.9 2.8 4.5 1.3 1.8 1.8 4:9 16.3 August August man 200 a iio Oo at ODD 09 doa AOD aud ht 0 St xt Oud oan att tad dda a ano anAD Haw dod ooo ada oot aw st xt te 6 6 60 od oan al tad daa 13.6 Total 2.6 3.2 10.2 7.6 6,2 Total YUKON Fr. FAIRBANKS Time of Precipitation in hundredths of an inch Time of Precipitation in hundredths of an inch 1.0- 109) .50- 099 -26- 249 .10- 225 April O.1 .01- 109 1.0- 1.99 .50- +99 +26- -10- 225 April .O1- .09 2,0+ Ite Month fe) 2.0+ +49 Tr. ie) Month 1.6 1.4 6.9 1-10 11-20 2.3 1.0 1.8 6.7 7.4 1-10 2 1.0 1.2 7.6 o.1 “7 11-20 Ald fo) ol bed 11D fat] a]wo ro) co) | a old mela ie jo Qe Ala hls a oly Ajo oly ld uu ola m]0 tye do UIE Mey 1-10 11-20 21-31 May 3 (a =p Rae eT} 1-10 11-20 21-31 Total 8.2 5.9 Q.1 4 §.2 2.4 22.8 Total 17.1 June June 1-10 11-20 21-30 2 -8 ZaF ae 5.9 eee) 1-10 11-20 21-30 Total O.1 6 x) otis ltset 1.8 2.2 6.9 5 20.2 OF 3.4 2.1 2.2 2.5 4 3.7 12.5 Total 1.1 2.3 8.2 5.5 July 1.3 1.6 6.9 1-10 11-20 21-31 July 1-10 11-20 21-31 Total 6.9 Wise 21.0 yi es 2.3 2.4 6.2 6.0 oe) 4 14.1 Total 1.0 2.6 August August 1-10 11-20 21-31 Total 2) Bee 2. 2.6 2.1 2.1. 3.9 3.7 4 1-10 11-20 21-31 ath 6 -9 aC Re eal 5.3 17.5 2.8 17 Tio’ 8.2 pal Total pO Bk f the month--Continued of occurrence by decedes of (Av. 1950-58) clesses, according to frequenc Table 22.--Precipitation intensit + ° 3 ct det a) a a . nol 7 oj! oO Blio da fet FIO O 12 O|M AIO oO A le let ° ° oe Aad ht Fl ae : z ale ° aie 3 eet 3 4 is] a aa} “4 an 8]o m ° wf? alou rt et ola a to al a lw a (ol at fo m0 410 IO co 4} rt tals aril yt tt at |o sive herd Beara bars : a bi oe ° ry ° : ele vee siiaeprs ize Pierce) pers uw ° ‘ Be or ee aloe ‘ a f=) a ° ct rif =| ° o e We} a a) o wo; t oll ole 4] HIS & £100 Or aia dale idan iInqale ja qae AA vedio iia je jeer jagai foarte I cil at ele joie alr. 3 3 dq fa 5 [S) dq dt rt rifal J [o) et eee | a a 5 lol \ et ard 4] 4 et ral o bl} ‘ » Ald wl be} o b] an Ald wl o bl 4 He @rila ble riciin gleam ojo jt ritala wisi colo BE UBIS TIO glo mol girit iin ja weil Ble rj lay cif UPR rf culo Hlataol~ lo staly Bla ilo bere bird eee bats ati bard oyketie| se erie ele e ef Ade ce ele) | Safe eel ve eiiehete| xe eleeie|ie ene bars Booed |=4 aia fe B[vececeles ‘Blow gi ele re hat qo 4 w al (St) kh Arita iy Ay iS =|D AO alo El og} [wh ale oo alo a © ho sto Olay & og] feeds a oO i} Vo alo elt tsi Mt cut AM rt fio ea fa rd tlio ey Joy a cut A 00 t9}c0 At tls at fio By fal aft a al 4 alo al al ale a o| eels uM aura an ela oO tio It cy wo] o| Ine ain I~ th cole oO © «o} O19 Ole é wd Old (Co) Hw ol 19 uO soe nis |ice vinte ove|ine ehatesicre iu! Gand |g Pier fi) Boker bie ° Ae se ele aiayeinye | oe ° vie bas ° cereiner [a 2 Y ee ee © © ©] Im 09 w]eco lo =H fie to 19 fra 19 Ht stat sts tro seat sto 1200 Io oo hla © 10190 19 10 i a st rA ct rel et rt i 8 N bE FA NS 3 g =] 4 9 alc oO let 9 Ql Oo [rt °o Art c 9 Ql oO let 2 Qlet O° let Oo rllret 4 ool on tg] @ B} Jo VM] g O48) g oUMlg oo e/g ot] y 9 RB) loMmly OV OM 4) q oN) a oH ely #| Joa mia oan’ isi i=] ett ty eat 8 Cn LL ett rat a isi eee ie ee ett ot Le Ge ent Sieh st rt ft tie et tip |e 94 0 Vet lo tt fo tet fo Vet lo Vet tf oO trl 44 O Vet aie Vet Alo et lo rt Ao Vet Alo ° teal Re) Trt fo ler Oo Sy det et cules eet let ee ae ules eet cles Ale Oo Sl tet cules ett les eet les at ley at ules m0 Sa tet et cules at le + + ° ° 4 al a a < cl Pio ol] | oD 1o oo O dq fa BJO o qa fa dela FIO O rit wllet et ° qi °. al"! et ° ' aa] “alt lO Oo 98]o o]O OD O}ia oO cle cust ra too 19 @fio nl(2 2) Iriel ta a rilar Ae 10 i]s © 0 wha al? ® et Vt aloe Om lo a f) a 2 o fa =| ° i] GC Lu ao we} o o mo) I wo] t wt @}.O ee AS & Aust) [ett jo MU Afro a ast A «0 co]co © 19 Ia aa] Jeo alo A cufio 0 © s/t Aa blo em 19 1O}sH cy st rt ijou Cot [oe HO mH g ° qi fa 4 ° fa fa dla 3 ° ra vy a & & re ® by] » Ale ole ~p si} t det a g bl | et a AHO tobe bo} oD na ATO WO] ret o b>] vd aye gles ajo Blt raln Biriw wiry Biri ilo asa sere gto gorau lomo" pln a rij aA RIN HHO iris tla gia olin loro) Mo w alt 8 fal qi ri to Bit rf t}co 9 =i|O [ov] ec) CV) (| (Cr = | | 9 ete (ho oO oOlo It co Ot °o os old mW wo] A |e iM st O] co MA OlO 5 Oo st ayo rt st Ort eo HO OM 9} Ah& hwo 0 0 ol> ho xt sat] tt x0 thst sot to 12 too 10 tt tt 1 xt xt 1 st who 19 1 Oo st 0 tt] =tt xf 10 wo] tt © 10 ol 10 in 10 10 tlt a ait q - rt cl al qt dA ca qi fa A a rt Pa a a 9 gla ° let ° Ola oO Ir od-r 2 9 Qlrt Onl 9 gle O let oO dle fa a rome) tal Aled 2 Ie oO let 2 #8] joa mlg oyelg oye] Oo MO] on ]'g 2 P] jou mg oye ou Mm) g ou M]'g oO 4 ]'g gJo 6! loarl’d oO 4 fla IO 1] "g oul 8. 8] lat t ott rit t oth tl4 at ide BH. st] Jat tle att alt l4 rol id aot ids Be Bf lst y we riot ida rot + ati Wi GV O tet A}o ' A} oO 1a] Oo 1 et Alo tet ayo Ofna ww O tet A] o let Ao lato {ret AO ae] oO rt GW O tao 1A] o [aro 1 A et] oO & Ol lar cules ett les et Oulet Ae alee ae les mle o sy fea et alles ct oles ee rt et OE rt ales paler O sal [at cules ett les ett Ole rit le 112 2.0+ 2.0+ 1.0- 1.99 1.0- 1.99 -50- 99 2 6 -50- -99 +26- 49 plaae of -26- 249 0.1 st -10- 225 April May June 4 2.6 July Au 1.3 -10- +25 April Ou7 A 2 1.3 5.3 3.5 3.1 .O1- .09 -01- 109 Precipitation in hundredths of an inch Precipitation in hundredths of an inch 6.6 7.1 6.4 8.8 2.9.2.5 8.5 7.4 2.6 2.6 2.9 2.4 3.6 1.9 9.1 6.5 8.0 8.2 le eece anf 2.0: 2.6 1.8 7.0 6.0 Tr. ie) 3.4 3.7 9.6 2.1 6.4 5.3 4.8 5.4 Total 15.5 of occurrence by decades of the month--Continued 2.5 Total 12.6 Total 11.0 Total 10.0 Time of Month 1-10 21-30 1-10 21-31 1-10 21-30 1-10 Total 1-10 11-20 21-31 Total SUMMIT Time of 1-10 11-20 21-30 to frequenc 1950-58) (Av. 2.0+ 2.0+ 1.0- 1.99 0.1 el el 1.0- 1.99 .50- «99 0.1 +50- Re? +26- 49 .26- 249 2.8 o.1 st -10- 225 April -6 ay June 1.3 8 LL 3.2 July -10- 225 April 72 O.1 2.7 5.8 -O1- 209 -O1- 209 ‘7 Precipitation in hundredths of an inch Precipitation in hundredths of an inch 2.2 lial. 3.1 1.8 8.7 4.8 3.3 2.2 Tr. 2.7 2.1 3.6 1.6 9.6) “5:9 Vea Sel 1.4 2.3 153° 3.3: ASS SBN. Ins ese 184 2.2 Cay) ie) (e) 5.8 4.8 3.7 2.7 3.6 Total 10.0 pallet g YA 3.3 1.6 7.6 6.4 7.3 6.3 Table 22.--Precipitation intensity classes, accordin Total 15.1 NORTHWAY Total 20.0 McGRATH Time of Month 1-10 21-31 1-10 11-20 21-30 1-10 Total 1-10 11-20 21-31 Total Time of Month 1-10 11-20 21-30 + ° fot) ro) ol 1 D Ald Dod te) lO D aaa | ce . pe | Darter : % 2 da ° i> 3 wt Cilome. fat] fal daa ao QUA ala on o]+ ol[2® a alu Sued bod 1c co ht o d da s io nu Pp a) ot K]O @ AM alo Ud at tot stfu Ow oi> gia uu jw ure Md Alo mt o> ao qm arya day Ala Pf °o Ala Addy oy ea d ~ b 2 a od b| © >) o 3 E aa FA s]t be 3 s dq a =a 3 “AO Wy] A = 3 3 maria Bydooln Blan old iB |OmerS |e g(t Uz|u ele mr {oO Blt aolo Bln dala 3B} © o]o dq Adal dials daa| 6 ° a 4 dale “Na dolls a P BA co Afro AM Ola Qh +} om Ala ‘jo o] [howe Oo A} tO alt oo t/q © 4 OI ddaujwo Aan Ae Ada} QU 2 ]00 “A ddalm jou tel be) Catinat] [red a a ° o ra tO }~o om olo th cy st]ro he Oe] & cg) Jaenia oo +|o dt old onda onM old cu 6 au foo QM Aloo aa do ddA Alwo 3 eo la cy 0 wo] tld ma culo Anao d a dq OW ala Oh alo om bo x tO} et ost olo hh ro ]ro oo olo tt O]H @ dala Coptrale) ies Simro) bers ape [ize Htion ico ° Sieur [tae ean |e i ° a iescwis | pe sisaee ho Ht w}io ta mlo ro MO nr © cy]co fa two st]< KO Ht | a & ta) 2 >| o st i >] s a FA © oS g ‘| a) “AO Ww] Q] 3 3 3 c=) Alt ose Bio wim Baral ajo Byxt i co [t= a2 s|[u de Siu rja Bite Ryo win 3/0 © elo Ajo Ala ddAyme @f a iw i) ° q a ia ala qa alt £ Be} ot un JP]a@ o Om Of hb © MI Aono sted 4]oo ‘dio Oo] Janne hu w}wo cut wlou co 82 ule lam olo 3 dq Cyst AA. I Cu (vai) [ad od ° au a Ae ddl ddd Anant BA 3) o ly et dt dlo KO cy coco Ot a] & +] [Om alr oarlau danlo DD A|m tr wo] 3 angie cis) ihe ees hs aoe: lela aoe a ties £3 trae) i ah aves Brat hel hi cimken ee ike seksi be o uN mw AN wulo cu cy cu] Ee] jad alo cu 4 cul cu cu cufeo aaae ua Alo a 5 WO O|D orn ola oa o}o co cu | mm to Ia AO) KU DH] 9m Oho c©on|o sieceian |e. stay ees |e wieteiire ire Erased bee ° * pene) bat selene Senco |e cas 3 oH 19 oO +h tet ola tH tt} tr ola ort KO «oO wlco ot tho ww Hho mt M]o o a d dq dq iat) a a qd a ° r4 1 2 © |x a liit Ore” WON |o ee Ws ae ce AO rt 4 Olr at Vt lo Ad 3 (9 Ale Ad dtet elle Arla a ele ata A u > q a rj ) ONUMM WORNMM est PIM OM Fo H/o Or Ho © ola B Jo |i] 2 to Ofte PVOERHKOAIY ar ONnUHaD HOM DO r1o OO UO A MIO — Heads Slwqww0w Woawardtals slonsonale BUBB stats ales BIN OY of st rt 8]i6 od Hs Filo BQ AMM WAI Bley iw om of rly eet ey acted Acad alet aetna aa vo g |o|s Aaa eaet Blt taal Sia alt et ae wo o © MQ xt co} VOM h a lo AVM Of wOl> PHONO rly Bla} jroo oolo 19H Ot &1O O19 1 GIO lO HK I9 alo Mm OM tO Mla rf OY 19 olay 1 19 th st 10 colm M10 rt et to] att 10 dA wy who aM or Aad to 000M 10 MIO at ilo or faa 1 diols eet et eifet ae foal tl Q adet a fal et a ‘ rt to atrt Ome wolH io) let al |jnocooo0l|n onmonrlo 7) i) qt rit rifst Ot 0 A) ie) E Fa BRC SCO} Beh Ol 13 Eat rit ro} rt [av] ooo line0000 loeg000 la00000 2020000 o00000 2900000 838838}. Sesaqe. S88saa|. SS0006 Ale hl |[2@S0G050].- Se0oG0|. A2S90000|. SOSOG00|. SOSSG05)}. 10.0 oP RAaAKDSaDS SSR RC UGS CONT The pebeditey Pabst tte Gh Q4 eaters a ea | [et pees Mie iad Ue pel ets A Pa Ih SERRE ICA LO aT ES ECR RO Fc er eto lad Sodan ala OOM ete Ula OOrlre wld mo eal loodrn ala 9OntA AM OOrdet et lat OOdet ead let OOnAA Me AN et al or et 4 aa st o Hoot cl ow | ° al med NMA IA tal oO a Pato ola AMO UO rao o fo Alka a UNDO |at tora ola At 19 9 w]o oavoh aly ° Aor dea aot lu waar Fait ° 1 10 rt] OO oO tho ath ost [to a | r tO > rio I tO 19 Oho lO WORE tle sig anor jt Caan elo KU Ow CY let tt ay io wo]to tO © ef Ola ce el “Gago we Aqrowaly o|t ° aorw |e 9 110 O10 aot 10 19 Oly {AMO HOMm|H ov ~ a ldbed ll ettesttret S| 712 | ea a a aetet et etl Arta ed 5 ” 4 a tio oaln ooaanoa|n Poor oaan|on B Jos ia ADAH JOodOr ay BUNaed arly Pra Q or a wrt Or OOM ri\st ao 10 Hloawaqwohs Baragcdn|d SIRE dana |i BRHwowsrle Shooraawls Blacovno lo BC 19 O xK wolay eget A RA AN 6 et Ae £ISi< Al dete a Blaed let las al taal lett rt tet Qt xt tlt ro xt st O & Oly it Ca (se) wot A AH O|D BIS) |waoun alo mo wom oh] eK Or CO xt PO] r4 OMG HH I/D ta © ofo ow the OM a et et wpe | ad taal Cs) et byt PALCouraegiscni cults Cy iO 1a 1S tM mt sit} ly led ate Ww aA A Met et g te a let cl 1 o]co © et bl rtlet 2 Ql [a ot a © alo Uc 19 HOY a) fa (ry QI et] eile i E ' ONO Det HO 1 et ty tlt i) id 8 a rele qt a ® e00000 loe90000 ee20000 loeea000 eo0000 838838]. B8e8aK8a|. S88sass. S8s8ssi. oa, mw IGOSGRG0 Se2e0000|. SOSG0G00|. O2S0G00|; Soq0q00|. 10 edt] baad 10 0 et] > RES C9 09 tee It tA M10 0 ri > Wid 3 9 BAYH o> Peds ic ae ba Ds Cai CYA CO ret 2 DQ 1) tle Poesia ea ait Nat Sonn aA ala SOntnANa OOAdM eA Mla 4 oO OOM eet Ula 9OntAAMIS OOnA et wl OOtAA Mla GOnAA Ml Table 23.--Air temperature by hour of day, and number of days per month in each temperature class--Continued (Av. 1950-58) GALENA GULKANA HOMER ae Temperature, degrees F. eae Temperature, degrees F. eee Temperature, degrees F. day 50-39 40-49 50-59 60-69 70-79 80-89 day 30-39 40-49 50-59 60-69 70-79 ‘80-89 day 30-39 40-49 50-59 60-69 70-79 80-89 April April April 0300 «6.1 2 0300 5.6 0300 16.2 12 0900 9:50. 2.4 0900 16.0 6.0 0-4 0900 17.6 10.3 0.1 1200 9.9 6.6 0.9 1200 11.7 13.8 9) 0.3 1200 12.0 16.7 one 1500 10.6 7.6 Le O-c 1500 11.1 13.9 2.3 ak 1500 11.6 16.6 1.1 1800 11.2 6.4 0) ae 1800 16.1 8.2 Bley) aah 1800 17.3 10.8 ne 2100 (10.3 oma 3 2100 _ 14.2 a0, 2100 21.1 2.8 Av. 925) 4.3 6 al. Av. 12.4 2 1.0 72 Av. 15.9 9.7 4 Ma. May May 0300 14.0 ote 1.0 0300 21.3 4.0 0300 18.4 CIBC) : 0900 3.8 13.4 10.3 a2 0900. 1.9) 16:1 12.0 1.0 6900) ase [25.7 4.1 1200. 2:37 7.8 14.2 5.0 0.2 1200 7) “O20 1459 5.0 0.4 1200 6 (22.8 Hirt) o.2 1500 2.3 T.8 12.4 1.6 =f 1500 +7 11.0 14.0 4.7 6 0.1 1500 9 23.2 6.8 el 1800 2.8 T.9 beets B 7.0 4 1800 1.4 T659 9.8 2.6 2 1 1800 eal 26.1 2.8 2100) 3.7. 1274 11.0 2.2 2100 10.3 16.9 2a) i) 2100 9.2 21.3 3 Av. 439910209 1022 3.8 2. Av. 6209 1255 8.9 23S: 2 Av. 5.4 21.4 3.6 sli June June June 0300 To leS6e 15.6 ae) 0300 6.9 19.1 4.0 0300 6.4 20.9 2.6 eal 0900 zal S22 15.55 (1021 pbeat 0900 258) 1Se7. 12.1 sheet 0900 10.3 17.4 eet 0.2 1200 1.0 CRS 13.2 ew 0.4 1200 1.3 8.8 1232. Tels 76 1200 6.4 21.0 se 4 1500 3 TO 13.1 8-2 1.4 1500 1.3 ese] abbey) ere 1.4 1500 6.4 20.7 2.6 3 1800 +7 Oe 13.0 yenal abee 1800 2.7 10.7 2 4.4 1.0 1800 10.0 alate 2.1 2100 1.4 12.6 13.3 2.6 -1 2100 9.8 14.8 4.6 -8 2100 220 119532 =) 10.0" 4 Av. 22 3.2 11.4 10.6 eat 5 Av. 122 6.2 10.0 8.5 3.6 5 Av ed 12.2 14.9 1.6 32 July July July 0300 6.4 22.5 2a 0300 2.0 19.2 9.8 0300 26 ele 7.3 0900 1.0 14.0 pike ee 2.9 0900 253 10.2 U5eT 2.8 0900 9 24.0 te) Af 1200 =2: 8.8 13.0 7.8 1.2 1200 ml 5.8 14.1 8.4 2.0 1200 EEO Crake) 8.4 ac 1500 =e 6.2 13.0 9:0 2.6 1500 -6 6.0 12.4 8.4 3.6 1500 Bie 20.5 9.4 «4 1800 fy 7.0 13.0 8.6 ene 1800 ee twill 13.8 6.0 2.3 1800 lal 23.2 6.7 2100 -6 13.1 13.4 3.9 2100 4.1 18.4 29) -6 2100 7.8 22.8 4 | Av. TFA VALO SLs 5.4 1.0 Av. aS. 4.7 9.6 10.7 4.4 13 ae AN 4 5.3 20.0 Sidi “2 August August August 0300 1.4 11.0 18.1 75 0300 4.7 20.1 5.3 0300 2.1 16.1 12.2 76 0900 5.0 20.6 5.4 0900 mae cae 17.8 87.9 el 0900 -8 24.5 Diet 1200 2.2 16.2 1152 1.4 1200 Led Love 14.1 5.6 1200 Be 21.5 952 Sak 1500 1.4 13.2 13.9 2.4 ok 1500 12 8.8 13.8 6.2 220 1500 ELH fi 8.2 1 1800 No) V5oe 9 114 2.4 1800 3.0 14.3 9.4 3.9 4 1800 -2 26.8 4,0 2100 al 3.4 21.9 5.5 eal 2100 cf 11.0 16.4 2.9 2100 BC} 9.4 21.0 4 Av. 2 4.2 17.6 8.0 1.0 Av. ee) 6.8 eee 8.2 2.56 2 Av. 4 4.4 215 4.7 ILITAMNA KOTZEBUE LAKE MINCHUMINA Time Time Time of Temperature, degrees F. of Temperature, degrees F. of Temperature, degrees F. day 30-39 40-49 50-59 60-29 70-79 80-89 day 30-39 40-49 50-59 60-69 70-79 80-89 day 30-39 40-49 50-59 60-69 70-79 80-89 April April . April 0300 14.6 0300 2.8 0300 6.9 '0.6 0900 16.9 5.0 (ojeae 0900 «44.4 0900 11.8 3.8 0.8 1200 14.6 10.2 Buf 1200 (Jen 0.1 1200 11.4 9.4 V2 0.3 1500 15.6 9.6 oT 1500 jar al 1500 10.3 10.4 2.2 4 1800 18.4 56. mae 1800 6.9 1800 12.1 8.0 1.5 3 2100 18.3 4 2100 4.3 2100 13.8 2.9 of Av. 16.4 iak 3 Av. 579) Av. 11.0: 5.8 lee 22 May May May 0300 23.0 5.6 0300 16.6 1.4 0300 14.4 nny} 2.0, 0900 Meyh) 19.3 Gat O-L 0900 16.0 5.9 Wad: 0-1 0900 3.4 16.9 10.8 2.0 1200 4.0 17.1 9.4 4 1200 15.1 8.4 1.0 +3 1200 «2.0 8.8 14.2 5.4 0.3 1500 Say, 16.9 9.3 alexa} 1500 15.8 9.0 ihe 1 1500 1.8 7.8 14.7 6.0 ot 1800 6.6 19.3 4.8 3 1800 16.9 Ted: “6 1 1800 216: 10.1 13.8 4.0 4 CLOOLE LT 1258 eile 2100 (17.7 3.4 =e 2100 4.2 15.8 8.9 aE) ol Avewa LO. Ano .2 4.6 73 Av. 16.4 5.9 af ee Av Cs as bs BP a Wo) 3.0 22 June June June 0300 4.2 23.5 2.0 13 0300 11.7 13.2 4,2 ae 0300 1.3 14.1 13.0 6 : 0900 °o 21.9 14.6 2.8 0.4 0900 9.3 12.6 6.3 are 0.4 0900 2.6 13.4 11.3 Hb 1200 7.4 16.2 5.1 270 0.3 1200 7.1 12.8 8.0 1.8 +3 1200 1.2 G2) LS 6.6 0.3 1500 7.1 13.8 6.8 2.0 -3 1500 5.3 12.3 10.0 Yap 3 1500 1.0 6.7 15.1 1.0 2 1800 1 Syn Sek) 5.1 1.6 2° 1800. 6.7 11.5 oot, Penk 1800 a9) 9°89 «2825 bint ne 2100 wo LTS 99. D7 73 2100! 8.7). V7. 8.3 1.3 2100 3.9 16.0 8.7 hea Av. SB MgLAS9" 116 3.6 9 12 AV. 8.1 12.3 18 1.4 2 Av. 72 4.0 11.2 10.6 3.9 a July July July 0300 18.3 Ab 0300 1.0 12.0 16.7 USS 0300 ak 8.2 20.5 252 0900 251 20.6 7.4 3 0900 -3 10.6 14.9 4.6 ak} 0900 8 1229 12:39 4.3 el 1200 Let 15-5 nb hy) 2.8 1200 6.4 16.6 tod -8 0.1 1200 6 8.3 13,1 Tad 1.9 1500 1S. 14.5 11.0 3.9 -3 1500 5.6 15.3 8.4 eet! 1500 3 6.3 13.0 8.4 3.0 1800 nis) nly et) 8.2 3.3 1800 an Gre. 15.5 8.3 oS} 1800 3 8.4 1257 Tid 1.8 2100 6.0 21.1 3.9 2100 2 7.9 17.8 5.0 al 2100 Dee LOB Le ick Av. 5.3 alr é-Le) Geo) nay A -l Av. ee) (Jha) 16.1 5.8 ae Av. ARE) 1270 10.8 5.1 Lez August August August 0300 .6 1250 18.3 0300 BlEAE 15.6 13.6 eae 0300 1.3 13.6 15.4 at 0900 Pe eee 5.0 ail 0900 oe 928° 18.2 2.8 0900 4.4 18.2 8.0 4 1200 6 18.4 11.0 7.0; 1200 8.2 18.7 3.8 3 1200 ae. 13.3 aebarh 3.4 1500 A nly (yd 11.6 Lat -1 1500 6.6 19.4 4.6 4 1500 13 11.5 13.3 4.6 +3 1800 a 219 Tae 8 1800 ae 7.3 20.0 3.4 2 1800 258 16.1 10.3 Bint pak 2100 ol 5.6 24.0 1.3 2100 4 ps ALS} 18.0 8 2100 2 6.6 18.0 6.2 Av. a of +) 20.6 6.0 6 Av 4 9.9 18.0 2.6 1 Av. 3 5.0 15.4 8.4 1.8 oe 115 Table 25.--Air temperature by hour of day, and number of deys per month in each temperature cless--Continued (Av._1950-58) McGRATH Time of Tempsrature, degrees F. Tempsreturs, degress F. Temperature, degrees F. dey 30-39 40-49 50-59 60-69 70-79 80-89 dey 30-39 40-49 50-59 60-69 70-79 60-89 "950-59 60-69 70-79 0-89 April April April 0300 0.4 rin ee) 0-2 ONT: a 0300 4.8 0.3 13.9 Ce 0.1 14.8 9 0.7 1200 11.0 9 0.1 11.6 11.2 2.0 11.8 < 1.6 0.6 1500 13.1 -6 -6 11.0 12.0 2n5, 0.2 12.0 -4 2.0 4 1600 10.3 6 3 13.0 10.6 oe) 14.2 8 oi) oe) 2100 2.7 2 16.3 3.0 ait 20.0 «4 .2 7.0 aul He 12.9 7.5 a9 10.9 -0 ee) 22 Mey Mey 9 8 -0 500 17.2 6.6 ° at 8 8) 5.0 0200 2.9 tel 9 1 oa 5 0.3 4 7 12.8 aheid 1200 1.3 8.4 ak 5 9 9, -6 2 ff 11.9 ene 1500 ulext 8.2 1 5 2 6.1 -3 .4 ti 9.0 -2 1800 2.8 11.2 9 o 2 LB -6 9 9 1.0 2100 Wet 16.5 6 74 10.4 3.7 22 -4 7 6.6 Bt/ Av. 5.8 10-5 3 a) June June June Si 16.4 959. -6 0300 Cr 3.0 cit 0300 1.8 17.8 10.1 3 3.2 14.1 11.4 1.3 0900 -6 2525 2.4 0-5 0900 me 2.35 10.9 14.3 ere 0.1 ae: 10.1 a259 5.5 0.6 1200 15.3 tine 1.6 0.2 1200 1.8 6.9 13.5 tee -6 ot SA oes 7.4 1.2 1500 14.5 9.1 sil -6 1500 6 eOr S29 6.9 -6 2 9.4 12.5 5.9 1.0 1800 15.35 6.2 1.3 35 2800 9 10.6 12.6 4.6 -3 i 15.2 10.3 i 2100 1.0 13.3 1.3 -5 100 oil 8 17.6 6.5 we -5 4.3 3 9.9 3.5 5 7 ee 12.8 4.4 a) o2, 3 2) 10.5 10.2 3.5 -3 Jul July guly 0300 6 10.8 18. Eo 0300 as ig. 11.6 aE 4 16.3 0900 4.2 19 1 os00 3.2 21.8 Beg i) 10.2 1200 -5 8.35 4 6 i) 1200 1.0 14.0 13.1 CIB xe 5.8 1500 7.8 3 8.1 2.8 1500 -8 12.3 12.6 4.1 ae 5.3 1800 3 8.3 5 6.6 2.35 1800 1.4 15.8 10.4 3.3 al 9.0 2100 1.2 15.8 at 2.4 She 21 4.2 18.8 1 2.8 13.0 -8 4.2 ata 5.2 16.1 Ted aT -3 oul 10.9 Au August ee ey ee Es ee es 0300 oUF Bef 14, -6 0300 -3 12.3 17.7 at 0300 5.1 8.1 x Sal os00 -0 20. 5.8 0300 1.9 23.8 3.2 = 0900 Je 5.1 a 8.8 as 1200 -2 15. 11.2 2.7 1200 ve 17.0 11.7 alary 1200 2.4 6 14.9 a5 1500 10) 12 13.3 ergal 2 1500 4 14.8 Te) 2.8 1 1500 1.8 1 12.4 6 2 1800 =) 15.0 BET, 2.3 L 1800 6 19.8 9.4 ee 1800 Ace -3 10.0 Shy aa} 2100 oe = 20.6 4.0 2100 det 23.2 eit 2100 peel 12.4 6 2.9 Av. 5 -8 16.3 7.8 1.5 i Av. aL 3.4 19.5 7.1 = Av. asa fale 1 8.2 2.8 oul smact TANANA UNALAKLEET Tine Time 2 Time 7 of Temperature, degrees F. of Temperatures, degrees F. of Tempsreture, degrees F. dey 30-39 40-49 50-59 60-69 70-79 80-89 day 30-39 40-49° 50-59 60-69 70-79 60-89 April April 0.1 030 4.2 0-6 0500 «7.6 0-4 1.6 0800 10.3 4.0 0.8 0900 11.2 2.3 4.0 0.35 1200 10.4 7.6 2.0 0.3 1200 12.4 4.4 0.2 4.4 -3 1500 9.6 8.8 CBU oil 1500 12.4 4.9 =e 2.3 al 1800 12.2 5.7 1.4 2 1800 11.7 mae) a) 2100 10.4 2.0 ‘3 2100 10.3 -6 rel eat AV. 9:5 4.8 aley-3 Ee Av. 10.9 2.6 eal = Mey Mey May y -0 :) 0300 14.8 9.9 +5 0300 16.9 7.6 za -2 1259 3.4 0.1 03900 4.1 10.1 TS) 2.8 0900 9.8 mS) 5.3 0.9 O 14.9 at a, 2200 2.3 fall” S28: 7.4 0-8 1200 8.1 13.7 5.7 GE) 6 13.7 7.4 Sth 0.1 1500 eal 6.2 1229 8.3 a. Onl: 1500 9.0 11.8 6.8 BICLe 0.2 1800 10.0 14.2 5.2 a4 alt 1800 2.1 Hien 13.3 6.3 8 1800 10.1 11.0 7.0 9 2100 17.7 8.9 2100 6.3 13.1 8.9 el 2100 14.2 10.7 2.6 Av. 13.2 10.9 3.6 3 Av. 5.3 9.0 10.2 4.3 4 Av. 11.4 11.3 4.6 &) June June June 0300 10.0 18.35 1.7 0300 3.1 14.5 11.2 aed mall! 0300 4.9 18.0 7.0 ape rey ashi eaulys 4.6 .3 0900 Usa 1222. 13:0 3.4 0900 1.6 8.8 15.6 3.6 x) 0.2 oil 4 12.2 Tet, ait 1200 otf 7.0 1229 8.6 =8) 3200) qake 6.9 15.6 4.4 8 on! ' +4 6.3 12.3 8.3 2.7 1500 as) 4.8 13.4 9.2 225, Y1500) #2 6.9 15.6 5.0 1.2 oul : at 9.0 11.8 Ligh 1.4 1800 wt 6.4 14.8 re! 1.0 1800 1.8 7.2 16.3 3.6 1.0 1 O29 SEB ELOSS: 2.3 ol 2100 5.0 14.4 10.8 1.8 2100 2.2 10.5 16.0 1.4 ou 2.6 ase Ost 5.0 real Av. a) 3.5 9.3°" 12:0= 5.0 ale egw 2.2 9.7 14.4 3.0 -6 aul ¥ July July 4 0300 2.0 22.7 aS 0300 1.7 12.9 15.1 1.3 0300 if) 10°65) 1859 -8 0900 9.2 -5 6.3 3 0900 Of On et As9 4.3 -1 0900 2.2 18.3 D5 x) g 1200 4.6 5 8.8 3.1 1200 4 5.9 13.1 9.8 1.8 1200 1.2 17.6 10.4 1.8 1500 3.6 1 10.2 4.1 0.1 1500 pel 5.0 135.1 10.0 2.8 1500 WO) AG7 Aen 1.2 , 1800 5.1 8 7.8 3.3 1800 -3 5.8 13.9 9.0 2.0 1800 1.5 19.6 9.1 1.0 2100 1 PAT: 1 4.1 2100 ghee sees G7/ 2.3 2100 2.8 23.5 4.7 Av. 3 9.5 2 6.2 1.8 Av. a) 2.6 9.4 11.7 5.9 atcal Av. ote 3.2 19.3 7.6 8 Augus® August August } 0300 5.7 21.7 3.6 0300 3.9 14.9 10.8 arf 0300 1.3 13.1 16.3 -3 0300 wt DANG e Set 0300 +2 5.0 16.2 9.6 0300 4.0 23.9 3.0 ol 1200 +4 7.3 16.9 ~9 1200 ol 1.6 12.3 13.3 3.7 2200 2.3 21.3 6.8 -6 1500 eS 6.9 16.8 1.6 1500 1.5 21.2 15.0 5.2 -5 1500 21 2182 7.0 -6 ot 1800 .6 9.8 15.8 34 1800 2.4 13.9 12.0 Sit 1800 2.8 23.1 4.7 4 2100F 125. 2 18t3_ 028 2100 1.1 Cae! 4.3 2100 -6 Meommeond 1.1 Av a EE eee bee Ee Pe) -5 Av. 9 5.6 13.6 8.8 259) -1 AV. -3 5.3 21.3 3.8 5 1/ Tempereture frequencies below 30° F. were not compiled. All stations in April and Mey, and Kotzebue in June had temperatures below 30° F. Source: United States Weather Bureau coded date. 116 Table 24.--Normal relative humidity according to time of day Percent relative humidity Station April May June July August 0200 0800 1400 2000 0200 0800 1400 2000 0200 0800 1400 2000 0200 0800 1400 2000 0200 0800 1400 2000 Galena 70 72 62 68 tae 65 51 58 76 64 49 54 82 73 59 64 85 82 65 75 Northway 78 62 49 68 81 55 43 61 83 60 48 61 87 67 50 66 89 71 52 75 McGrath 77 70 55 66 82 66 49 60 84 67 50 59 88 75 57 66 92 86 66 as) Fairbanks 74 63 47 61 tT 57 42 55 82 62 45 57 88 70 52 66 91 78 57 Giri Anchorage 75 67 53 67 77 64 50 63 75 68 57 65 85 74 62 72 86 78 65 he Naknek 1/ 86 80 64 78 86 73 58 75 88 78 59 T2 on 82 60 75 92 86 64 81 Bethel 87 84 74 83 89 r9 64 74 90 80 64 70 93 87 69 Tele 96 93 aA 87 SSS eee 1/ 3 years of data only Source: United States Weather Bureau. Local climatological data, Alaska, 1958. 117 Table 25.--Relative humidity percent by hour of dey, and number of days in each temperature cless (av. 1950-58) ANCHORAGS BETHEL BETTLES a Relative humidity percent are Relative humidity percent pana Relative humidity percent day 10-19 20-29 30-39 40-49 50 day 10-19 20-29 3-39 40-49 50/ day 10-19 20-29 3-39 40-49 50 April April April 0300 O22 1.3 28.6 0300 30.0 0300 0-2 0.2 29.7 0900 +2 1.2 5.0 23.7 0900 tats EE) 03900 od, 2-9 eI.O, 1200 +2 3.2 9.3 17.3 1200 0.2 ee) 12857, 2200 A) 4.2 24.9 1500 6 4.3 320) 26-0 1500 eek ae oereuert) 1500 -7 4.8 24.5 1800 ae 2.2 6.1 21.5 1800 sO ore 1800 =a 3.4 26.5 2100 0.1 of 1.8 27.4 2100 30.0 2100 el =6 29.3 Av. 2 19 5.4, 22.5 Av. -6 29.4 Av. -3 eatneod 0) May May May 0300 Et ip He 0300 31.0 0300 0.2 -5 30.7 0900 2 1.6 6.3 22.9 0900 onl -7 3.2 0900 6 5.2) 125.2 1200 6 4.7 11.6 214.1 31200 0.2 8 4.4 25.6 1200 2 3.4 6.8 20.6 1500 va 6.7 10.2 23.0 2500 x) 1.8 4.8 24.1 2500 8 3.6 7.4 19.2 1800 sth 2.6 8.3 19.4 1600 0.2 el 8 3.4 26.6 1600 -7 3.4 6.9 20.0 2100 eek -6 2.9) eTes 2100 1 oul <7 30.2 2100 Pt) 3.9 26.2 Av. 4 By Simoes Av. on 26 2.3 28.0 Av. a) 2.0 5.20 23.6 June June June 0300 3 2ou7 0300 eee 29.9 0500 4 29.6 0900 3 2.6) Tet 0900 -6 29.4 0900 ot a Dede eesS 1200 ot 2E 5.6: 22-9 1200 1.3 2.4 26.3 1200 x 5.1 8.2 16.6 1500 -6 1.6 8.4 19.4 1500 4 1.6 4.4 23.6 1500 1.8 6.2 6.4 15.6 1800 1.6 6.4 22.0 2800 .2 8 4.1 24.9 1800 2.2 4.7 5.60" 27-5 2100 -3 2.4 28.3 2100 -6 29,4 2100 .3 2.8 2.8 25.12 Av. = 8 4.1 24.9 Av. aa -6 AS eae 3 Av. 8 3.3 Ey SS July July July 0300 31.0 0300 31.0 03500 wt 30.9 0900 diet 1 seoss 0900 ea. S059. 0900 T.8) 29.2 1200 4 4.6 26.0 1200 oa 2.3 28.6 1200 2.8 6.9 21.2 1500 ae +x) 5.3 24.6 1500 8 3.6 26.6 1500 4.6 6.3 19.0 1800 8 4.2" 2652) 1800 8 2.8 27.4 1800 3.9 6.0 20.2 2100 -6 30 2100 2. 30.9 2100 7 2.3 29.0 Av. Ce leS AV. -3 nSS ier ooc) Av. 2.0 3.7 «24.9 August August 0300 5 Re) 0300 31.0 0900 8 30.2 0900 31.0 0900 ot 30.9 2200 4 ART te AS!) 2200 -2 30.8 2200 -5 2.0 28.7 1500 cel ot 4.0 26.2 1500 mae -6 30.3 1500 -6 4.0 26.4 1800 <2 2.6 28.2 1800 ort -7 30.2 1800 -8 TI) eS) 2100 3 30.7 2100 31.0 2100 31.0 Av. =o ce) Av. SS ErCOlT, Av. .3 aeeimegeo EIG DELTA FATREANKS Fr. YUXON Be Reletive humidity percent Bre Relative humidity rat Relative humidity percent day 10-19 20-29 30-39 40-49 50/ day 10-19 20-29 30-39 40-49 50 day 10-19 20-29 40-49 507 April April 0300 O21 0.9 29.0 0300 0.2 O=tipaekee 0500- 0.4 28.5 0900 0.2 2.0 Tet, 20: 0900 0.2 2.4 6.23 eine 0900 4.35 25.6 1200 O21 1.6 4.1 8.7 15.5 1200 i.e 4.3 9.7 14.8 1200 627, 2259. 1500 1.6 4.9 8.7 14.8 1500 2.3 6.1 8.8 12.8 1500 6.9 20.2 1800 ae 2.8 5.9) 2723) 1600 of 4.3 8.9 16.1 1800 2100 -4 Dede Oe) 2100 4 3.2 26.3 2100 2.0 26.6 Av. 6 2.4 5.8 2is2 Av. aie 2.9 6.5 20.1 Av. 4.1 24.6 Mey Mey Mey 0500 ERE 8 Azo, 28.2 0300 1.0 30.0 0300 ad. oz 1.4 29.4 0900 1.4 Gon 8.7 13.2 0900 6 7.0 8.7 14.6 0s00 -3 2.2 7.9 20.6 1200 ant 3.9 929 320) 8.1 1200 0.3 5.0 8.4 8.4 8.8 1200 6 5.2 10.6 14.7 1500 cae 4.2 10.9 hoe 8.6 1500 -4 6.35 10.3 7.3 6.6 1500 2-3 6.8 10.2 12-8 1600 2.3 8.5 6.9 13.3 1600 ii 3.7 8.8 9.4 6.4 1800 Data missin; 2100 1.8 fe6i. 321.6 2100 -6 2.0 5.7 25.8 2100 -2 714) 5.8 Av. 2.0 6.4 7.1L 15.5 AV. aa 2a 529 6.8 15.4 Av. -5 3.2 7.2 June June 7 June 0300 at -3 aL Byers 0300 -5 =9pi28.8 0300 axl z 24.9 0900 BE) 4.3 Ted SUTST os00 od: -6 3.7 7.2 18.5 0900 Be! 3 17.6 1200 el 2.7 6.8 8.9 25, 1200 sul 2.9. T.7 8.7 10.6 2200 < 6 13.2 1500 ade 4.1 6.8 728) ade 1500 ef 4.4 7.9 8.1 8.9 1500 2.0 6 10.3 1800 ae etl 5.8 7.6 14.1 1800 -4 3.0 2 729) 2455 2800 Data mis 2100 “1 2.0 5.3 22.6 2100 Zit) 4.4 23.7 2100 a) 2 20.7 Av. ed 1.7 4.3 6.4 17.5 Av. -2 1.8 4.8 6:2 720 Av. 4 4 17.3 July July July 0300 al 2 eer eosn 0300 31 0300 2) 1.30 29.5 0900 ut 1.6 6.6 22.7 0900 ot 1.2 4.0 25 0900 @ 2.2 8.2 20.4 1200 a6: 5.2 8.3 15.9 1200 UT 5.2 WO} faz, 2200 -6 3.3 22.0 15.1 1500 oi 2.2 6.7 7.7 14.3 1500 .3 3.2 6.0 6.3 15 1500 Ey 4.9 10.7 14.7 1800 ) 5.4 7.2 AGS 1800 2.2 Sse 7.0 16 2800 in, 21200 =e 1.4 3.0 26.4 2100 -6 alte) 2200 2.2 By fa AY / Av. 8 S.4 Sotsepedied Av. ot ane, 3.0 4.2 22.5 Av. 2.5 7.6 20.5 August Augus? Auguss 5 et 1.4 29.5 0300 0500 2 «630.8 of 4.4 25.9 0900 od a2 0300 otf 2.6) 27.7, -3 4.2 8.0 18.5 2200 6 Sa 6.7 1200 cal 9 8.7 21.3 +4 5.3 iy Ak 8 2) 1500 a) 5.6 6.9 1500 = ris) 8.9 20.0 a) 2.2 6.67 peis9 1800 1.4 6.2 1800 ta missing Ate 2.8 27.5 2100 2100 3 2.8\__ 28.9 Av. 2 2.2 5.3 23.3 Av. a} 1.5 Av. 8 4.4 25.7 118 Table 25 ,--Relative humidity percent by hour of dey, and number of days in each temperature class-~-Continued (Av. 1950-58) GALENA GULKANA HOMER one Relative humidity percent pie Relative humidity percent eee Relative humidity percent day 10-19 20-29 30-39 40-49 50/ day 10-19 20-29 30-39 40-49 507 day 10-19 20-29 30-39 40-49 50 April April April 0300 30.0 0300 0.2 O.1 29.7 0300 0.2 0.4 29,4 0900 Q-9) 8e9cL 0900 ol 3.9 2650 0900 0.1 +6 1.3 28.0 1200 0.2 0.4 4.2 Cone 1200 0.1 2.6 9.4 17.9 1200 rr) 1.7 28.0 1500 2 1.4 Aol | BEC 1500 6 3.2 10.0 16.2 1500 8 2.4 26.8 1800 cee $.7 25.1 1800 2 Pt) 6.1 22.8 1800 oe aie) Lid 283 2100 cist 6 29,3 2100 ol «3 290 2100 0.1 +8 29.1 Av. ods a) a eta Av. 2 De 5.0 23.6 Av. 4 Ys WebNS Mey May Mey 0300 1.0 30.0 0300 ile me 30.8 0300 ok 30.9 0900 8 rapat 6.0 Cenk 0900 o.1l ott 19 9.0 19.3 0900 ol 6 30.3 1200 0,1 ates) 6.7 Hed 15.3 1200 +2 2.6 7.0 TS. 13.3 1200 1.4 29.6 1500 74 2.9 6.9 7.0 23.8: 1500 =< 3.8 8.0 Ti 1L.F 1500 el ol 1.0 29.8 1800 3 2.6 5.6 Tee) 14.6 1800 se 1.4 4.9 7.38 Ue. 1800 6 30.4 2100 4 3.3 6.2 21.2 2100 4 2.4 28.2 2100 al 30.9 Av. ol 1.4 4.1 5.9 19.5 Av. aul 1.4 Sar, 5.7 20.4 Av. 6 30.4 June June June 0300 23 2907 0300 eae 29.9 0300 30.0 0900 4 1.6 4.3 23.7 0900 2 2.6 8.3 18.9 0900 al 29.9 1200 alt v8 4.2 9.1 14.8 1200 +2 3.4 7.4 8.7 10.3 1200 ol ot 29755) 1500 4 Ce) 4.8 8.1 13.8 1500 ah 4.8 8.2 6.6 955 1500 el ol ad eA) 1800 2 ad. 4.9 6.8 15.2 1800 +3 3.2 5.4 8.4 abe sy f 1800 -4 29.6 2100 ata l oe Sate 22.0 2100 ol 1.4 4.6 23.9 2100 30.0 Av. ol T25 cine 5.4. SL9N9, Av. “2 2.0) 4.2 6a LT Av. 7 12 29.8 July July July 0300 31.0 0300 31.0 0300 31.0 0900 25 2.8 OT 0900 269? 229.7) 0900 ol 30.9 1200 4 2.6 7.4 20.6 1200 29. 4.8 8.3 17.0 1200 +2 30.8 1500 ney) 4.9 7.4 L755! 1500 aE 2.3 6.7 8.3 13.6 1500 a) 2 30.6 1800 6 5.2 6.4 18.8 1800 Bae 4,4 6.6 17.8 1800 2 50.8 2100 -6 eae, 28.2 2100 +3 2x6. 28 2100 31.0 Av. 4 2.3 4.4 23, Av ee) 2.7 4.6 22.8 Av. ol al 30.8 August August August 0300 31.0 0300 31.0 0300 31.0 0900 -8 30.2 0900 15 9ee 291: 0900 ‘ al 30.9 1200 oi 1.0 2.8 27.1 1200 4 oe 6.1 eons, 1200 3 30.7 1500 4 Eear 2.8 25.9 1500 9 4.6 8.1 17.4 1500 12 +2 50.6 1800 aah 12 2.4 27.3 1800 9 2.3 4.1 23.7 1800 +1 30.9 2100 +9 30.1 2100 sol SOT. 2100 31.0 Av. a Hy 1.6 28.6 Av 4 as 3.4 25.7 Av al +1 50.8 ILTAMNA KOTZEBUE LAKE MINCHUMINA nae Relative humidity percent pate Relative humidity percent eos Relative humidity percent day 10-19 20-29 30-39 40-49 507 day 10-19 20-29 30-39 40-49 50 day 10-19 20-29 30-39 40-49 50/ April April April 0300 (Ober 29.9 0300 0.1 Oud 29.8 0300 0.2 0.4 29.4 0900 0.2 On COs 0900 aids eo29 0900 Ova: me 2.) eT.0 1200 «2 nee l 28.7 1200 30.0 1200 6 ret 5.9 21.4 1500 ak 1.1 28.8 1500 0.2 +4 29,4 1500 +6 3.3 5.9: 20,52 1800 Hel 29.8 1800 cal el 29.8 1800 2 2.0 7.4 20.4 2100 ok 29.9 2100 30.0 2100 8 3.2 26.0 Av. ml -5 29.4 Av. ra ol 29.8 Av ace 1.4 4.2 24.0 May May May 0300 31.0 0300 31.0 0300 eae fc} 30.0 03900 Fk) 30.4 0900 eel ff 30.2 0900 Fi} 1.4 0 22.38 1200 QoL eels abe} 29.0 1200 <2 8 30.0 1200 1.4 6.2 + 8.8 14.6 1500 0.1 ee -8 ee 28.8 1500 ol 1.0: 29.9 1500 3.4 4.4 10.0 13.2 1800 31, 12 alo} 29.7 1800 ni 30.9 1800 Oe 1.3 4.6 talpal 16.8 2100 3 30.7 2100 31.0 2100 i) 1.6 6.2 Cea. Av. Bal -2 8 TRE) Av. wl A 30.5 Av. ea 3.1 6.8 20.0 June 5 June Juns 0300 al 299 0300 30.0 0300 is 8.4 0900 ol ne eat 0900 4 6 29.0 03900 1.4 6.3 22.3 1200 od ene aly 15159) 1200 a0. t 29.20 1200 2.0 5.8 8.1 14,1 1500 elt Epa 3.9 24.9 1500 1 ar) A 292 1500 nl 2.3 T.8 6.3 13.5 1800 oe no 2.4 26.5 1800 ade 36) 129.3 1800 -9 4.7 Ted aly (sa 2100 me of. 29.0 2100 On eS ST 2100 cab 1.3 4.4 24,2 Av. eal oa) 1.4 28.0 Av 2 4 29.4 Av. ae) 3.5 5.7 1959 July July July 0300 31.0 0300 31.0 0300 +3 30.7 0900 ot 30.3 0900 31.0 0900 ral oe 2.8 27.4 1200 3 ie Olmme oss 1200 8 30.2 1200 A 3.4 6.9. 2159 1500 pe ale 2.6 PHOT 1500 1 29 30.0 1500 1.2 5.4 6.7 TSS 1800 ohh aa) 28.1 1800 a) 30.7 1800 3 4.8 5.6 20.3 2100 aa: 30.9 2100 al 30.9 2100 8 i eee Av. 3 2 29.5 Av. 4 30.6 Av. 3 2.5 4.0 24.2 August August August 0300 31.0 0300 31.0 0300 31.0 0900 pe 30.9 0900 2 30.8 0900 oT 30.3 1200 nae Ae) 30.0 1200 od iC 30.7 1200 a Seo et.o 1500 ee Toe oT6 1500 ol a 30.8 1500 ail 9 4,4 25.6 1800 1 6 30.3 1800 23 30.7 1800 1 2.6 28.3 2100 al 30.9 2100 31.0 2100 we 30.8 Av. oi 30.5 Av. al 30.9 Av. 2 1.9) (28.39 119 in eech tempsreture cless--Continusd Table 25 .--Reletive humidity percent by hour of dey, end number of days (Av. 1950-58) McGRS a Reletive humidity percent = Reletive humidity percent : Relative humidity percent dey 10-19 20-29 30-39 «40-49 50 dey 10-19 20-29 30-39 40-49 sO/ dey 10-19 20-29 30-39 40-49 507 April April April 0300 0.2 29.9 030) 30.0 0300 0.2 0-2 29.6 0300 eee reel, os0o 0.6 29.4 os00 «0.2 0.2 pala 4.3 23.3 1200 2.6 6.6 20.6 1200 0.9 2.4 26.7 1200 real 3.9 Eleil 15.9 1500 3.2 8.2 18.3 1500 0.2 akan 2.3 26.5 1500 ai isa 4.6 10.2 14,2 1800 oul Lr, 7.3 20.9 1800 o2 1.7 28:2 1800 Sil 3 reid 5.1 22.4 2100 et pom Ne OT 2100 30.0 2100 al! 1.3. 28.6 Av. a2 1.3 AY 2455 Av 4 aOR Te ve aul a oe) 5. 0meera Mey Mey May 0300 -3 30:7 0500 31.0 0300 a pil 8 03900 3 1.6 7.4 21.7 03900 oll 1.4 29.5 0300 dat -9 6.3 8.1 6 1200 0.2 1.4 6.1 8.3 15.0 1200 4 1.3 5.3 24.0 2200 “4 3.8 6.4 7.0 4 1500 3 2.5 TT. 32 11.5 1500 <2 thestl 5.35 24.4 1500 a) 4.9 8.3 6.7 8 1800 pal 2.6 5.8 7.6 14.9 1200 2 4 3.0 27.4 1600 ue) 1.8 5.8 7.4 & 2200 oH) 1.4 453. 25.1 2100 31.0 2100 ol! -5 1.9 Uf Av. 2 Leal 3.6 6.2 19.8 Av. 2 29 2.5 27.9 Av. 2 Als) 4.9 5.2 8 June June June 0300 30.0 03500 Bist 28) 0300 30.0 os00 bal 1.6 SiG) “227. 000 che egy 0300 -6 3.2 920 Ree, 1200 1.4 5.3 82 15.2 1200 oul 1.6 3.2 25.2 1200 at at) 8.6 7.6 11.8 1500 1 2.8 7.0 6.8 13.5 1560 -6 9 5.6 ang. 1500 os) 2.1 8.3 7.6 11.7 1800 oh 2.3 5.8 5.4 16.4 1800 2 alae 2.4 26.3 1800 sil om 6.5 6.8 15-9 2200 -2 1.9 3.4 24.5 2100 oil 2929 2100 4 2) 26.7 Ave ay 3.6 4.9 20.4 Av. 2 8 2.0 27.0 Av. pak Eo) 4.5 5.6 1879 July Juiy July 0300 31.0 0300 31.0 03500 () os00 255.) 228.7, 0900 30.8 0300 ee eG 7 1200 ol 6.2 21.3 1200 9 27.0 1200 1.4 5.7 6 1500 1.0 6.8 18.9 12500 a 1.4 25.0 1500 «tl 2.1 6.2 7 1800 -8 4.7 21.4 180 ae 28.6 1800 out 1.2 3.8 Tf 2100 real 28.3 2200 31.0 “2 2 Av. -5 3.7 25.0 Av. -4 ey SEI -8 2.9 9 August August August 0300 31.0 0300 31.0 0300 31.0 os00 -4 30.6 osoo 32.0 000 1 3.4 27.5 1200 aif Ane} 27.4 1200 3 1.2 29.5 1200 -6 3.0 9.8 17.6 1500 bal aa, 4.0 25.2 1500 ol 3 2.3 26.5 1500 -8 4.5 9.4 16.3 1800 au 4 2e8. 2OTeT: 1600 -6 30.4 1800 oul, aad Ghee aor: 2100 el 30.9 2100 31.0 2100 31.0 Av. -5 1.7 28.8 Av. el SU) 30.2 Av. a2 1.5 4.7 24.6 sect TANANA UNALAKLSET Time a sae os Tine = aie Tine 5 ArH ae Relative humidity percent of Relative humidity percent of Relative humidity percent dey 10-19 20-29 30-39 40-49 507 dey 10-19 20-29 30-39 40-49 507 dey 10-19 20-29 30-39 40-49 507 April Ap April 0500 29.9 0300 1.0 28.7 0300 0.3 IST 0900 0.5 28.3 0900 2.8 26.8 os00 0-5 2.4 28.3 120) at 25.9 2200 0.1 eyed 23.3 1200 -6 1.35 26.1 1500 0-4 1.2 24.0 1500 aa 5.9 21.9 2500 4 ot) 28.7 1600 2 27.7 1800 3.9 25.0 1800 8 29.2 210 -35 2950 2100 1.6 28.4 2100 me 29.8 Av. eae 4 27.6 Av. ale 78 Seas Av. on Sommrcos0 Ney May Mey. 0300 2 30.8 030 9 i 0300 oul of 30.6 ogo 4 1.3 3.3 26.0 0900 at 3.2 6.2 g 0900 1.4 2.4 26.8 1200 gl hh Lt 4.8 253.7 1200 2.7 4.8 10.6 9 1200 0-2 1.2 S.1 (26.2 1500 a 4 3.0 5.6 22.1 1500 3 3.2 20. 8.2 -3 1500 1.9 2.2 26.3 1800 24 2.4 4.2 24.0 1800 a) 252 4.6 8.7 ne. 1800 1.0 2.4 27.0 2100 a eA 29%5 2100 el ue 4.2 -6 2100 1.2 29.8 Av. 75 1.4 3.3 26.0 Av. ae 1.5 3.4 6.5 5 Av. 5 a 2:0 27.8 June June June 0300 30.0 0300 ol! ae 29.7 0300 ol 29.9 os00 2 1.2 4.0 24.7 ogs00 +4 1.4 5.4 22.6 os00 6 1.2 28.2 1200 a 1.0 2.9 5.7 .20.3 2200 1.4 6.2 Teser BOs 1200 al .4 1.1L 4728.4 1500 oa! ae 2.9 6.0 19.8 1500 eat 2.9. 5.7 8.6 12.7 1500 8 yt) 25 1800 rhe 2.6 4.4 21.8 1800 ese 4.2 TL 16.5 1800 oe ae 2.200 28.5 2200 res +2 1.7 28.0 2100 a) ee 2 SBI COR: 2200 3 -4 29.3 Av. 6 1.6 Cy Aer al Av. r.2 3.1 5.3 20.4 Av. ow! 4 a9; 28.6 July July July 0300 ou 30.9 0300 31.0 0300 3120 0900 aa! 2 26 32922! 0300 2.2 28.8 0900 ne 7s 30.5 1200 5. 1.6 3.7 25.2 1200 a) 2.9 6.0 21.8 1200 oak Bey -6 30.1 1500 ot 3.7 4.1 22.5 1500 1.2 3.6 6.9 19.3 1500 oth & 30.5 1800 ati 1.8 3.4 25er: 1800 on 3.3 5.3 22.2 1800 .4 30.6 2100 TO OO at 2100 ol 2.0 29.9 2100 2 30.9 Av. .5 1.2 2.2 27.3 Av. .5 1.6 3.6 25.5 Av. eel 35 30.6 August August August 0300 31.0 0300 31.0 0300 31.0 0300 “2: 30.1 0300 30.8 0900 “2 30.8 1200 =f 3.0 27.2 1200 ate) 28.0 1200 -3 -2 30.5 1500 ol 2:9 (26:9 1500 5 1.6 24.7 1500 a) -1 30°65 1800 alent 29.2 1800 4 28.5 1800 4 30.6 2100 31.0 2100 31.0 2100: et SUES) Av. 74 1s 29.3 Av. ol 1.4 "29.0 Av. of 30.7 Source: United States Weethsr Bureau coded deta. 120 Table 26.--Sunrise, sunset, and duration of daylight Fort Yukon, Alaska Anchorage , Alaska Missoula, Montana Date Time of Time of Duration of Time of Time of Duration of Time of Time of Duration of sunrise sunset daylight sunrise sunset daylight sunrise sunset daylight Hrs Mins Hrs Mins Hrs Mins Apri — 1 0456 1836 13 40 0524 1843 13 #19 0616 1905 12 49 ital 0416 1911 14 55 0452 1910 14 18 0556 1919 13° 23 Al. 0335 1947 16 12 0422 1935 U5. 1S 0538 1933 13755 May 1 0255 2025 17 30 0351 2002 16 Li 0521 1946 14 25 ata 0213 2105 18 52 0323 2029 17 06 0506 1959 14 53 21 0128 2150 20 22 0258 2055 Jif gbit 0454 2012 alayealgs} June al 0033 2252 ee 19 0236 2119 18 43 0445 2023 15 68 lak 1/SAH SAH 24 00 0222 2135 19 13 0441 2031 2:5; 350: 21 SAH SAH 24 00 0218 2143 19 -25 0441 2034 1: 5S July al SAH SAH 24 00 0225 2140 9: 25 0444 2035 Algopemeny 11 0034 2252 22 18 0240 2127 18 47 0452 2030 15 38 21 0129 2200 20 31 0301 2107 18 06 0503 2022 a9) Aug. al: 0216 2115 1é 59 0329 2040 ky ental 0515 2009 14 54 11 OL57 2034 17 37 0355 2012 16) Av 0528 1954 14 26 21 0333 1952 16 19 0421 1942 WB. vel. 0540 1937 2S: 57 Sept. 1 0412 1908 14 56 0448 1907 14 19 0555 1916 1S. 21: 11 0445 1828 13 43 0514 1836 13 22 0608 1857 12 49 21 0518 1748 12 30 0538 1804 12 26 0621 1836 Je 15 1/ SAH - Sun above horizon all days Source: United States mimeographed data. 121 Wind direction (fron) jer month in each direction class and number of days Wind direction (from) (Av. 1950-58) Table 27.--Wind direction by hour of da: Wind direction (from) ANCHORAGE Time of Al On O rl moO Oi] [wr wi oO oly be NR DAUAARG Or ada April Calm 7 ie} 4 of 6 oO 4 2 WO x Ohio 3 ND 19 19 0d 0d Oto FA) e]O D 4 CY DIO I CU 19 9 QUIto Sted 2 tro sti tO 0d 03 09 Oho B] Jntormandin iO dAA ala Calm 4 6 8 3 3 6 3 4 th OU OI] tA Segepneme ne eltre HAM Ol Yt rh OM Ir Yala ¥ oly April A DO Ht Ad aa a ol A) lor ww + oho ea al el oo00000 esessso. C) BUH o A> a lOOHAANS May 0 = CY OLO 1 CU cy 19/19 KO HOO WO xO MmMANM ANY Am UM Oo s/o unm +t cia balla Ib oo) Haoadaela IM 2D YD XK it td 3/6 12 AO OW w\o at tcl st rd QO 12 QUI id wf his ahs L919 af 0d 03 ea] St QU 1 0 OJ wd roar ouronrnlt A © xt xt i]t COON ao Hor wow lt QOD Hc ld al 8 Fu walt ht OOM O|[M Cr) I CU oD «OP ]tO OD Kt HD DIO 09 0d Atle iTpoRonaln 9 3 A cd cd aif A UOMO Ort aa le OOM Ht TOD rHOOo oO who moO Ae A Old old ww dt tlt Im bt « COd AAS August st tc M1 Ht CULO to tM 9 00 ft HO OO 9 /xH OU AA allo wouon alr at Ir onwonls 10 0 Ww Fro Ce t tir Orr} > Ico. 16 wo tle i 3 Calm -8 OOD wo vy AMM mm yy W 3.8 NOM an ht xt 10 95.2 ONWMO Or Wind direction (from) 2.0 1.1 1.3 15.5 FT. YUKON Time of Av. 5.6 Ino O HY CO 129 19.10 Or 2.1 2.5 mAAM Oly MA A OO 2.8 Aa oon ala KO Dh M ~ ~o]c~o 32229 May 3.0 4.6 Wind direction (from) April 2.6 2.7 BIA) 3.6 2.2 5.1 3.3 4.8 3.8 9.7 94.2 FAIRBANKS Time of da: Av. Av. 4.3 3.3 2.8 Calm 3.1) 1.0 Ss47 251 5.1 1.4 SW SE April 5.5 4.4 Ma: 8.8 5.1 June Wind direction (from) tLe Olena Orestes tie 0 337 (1.6 5.8 1.3 -8 1.4 1.5 2.0 INADA OM Phe dq elidel UO 1919 tI Ww oar wlo I HOO Ht Ole Orr rooly lo-ownww WaNVANA Ae I~ aANote HAA AA 0300 4.0 a BIG DELTA Time of day Av. Av. 2.1 1.2 co. it 1.5 1.4 13S 8.9 Av. 3.0 5.5 2.9 5.8 6.1 1.8 1.6 Av. Jul ooh A a\Ko DG aaar|K at ]y A Ht oat A~AORA\o HOndw lo Ko 1 O Olt Jul Jul: At td gl alto eo BO OY 9 DI vada ‘Ja Ob tt rd too dadddddla ONO dts “aww w0 “0 Av. Ky 19 © 10 at OH w +10 KO Hw xt CO lt 0 O > 10 @/c~O COAX lw cl 3 od Fl cial st - Au ist Au August . . . 2:7 3558) 754 Sik 3 ice 8 (3.9) 252 426 13.5 3.8 1.6 4.8 3.2 3.6 3.1 257, dia, FGSE 2c) 4 6a a 2.6 ely) Tele iSet) 42 9e oad: 4.6 1.31163 -7.9 3.7 3 4.2 4.6 1.5 6.4 4.4 4.1 2.4 4.2 OOM rt rijto ddddeled WOOO Ht Ia rmUAN NY IC lO AAO welt it~ = Ow iD &]woO I~ UMM ORO aed Ade 0900 8 A 0200 1500 1700 2000 > x tAtahe on Im O99 0 4.8 AMeAANO st riaaw 6 hr UM em Hanvodta 3.2 3.1 Wm or aw AUdOo@ do ad 2.5 5.6 lomoOOnt 1 2 4 3 1. 2.6 2.1 Av. 2 7 6 8 7 . 2 1.5 1.9 2 Av. 122 See footnotes at end of table. Calo SW Wind direction (from) SE da; 1950-58) SW. SE (Av. Wind direction (from) GULKANA Tine Table 27.--Wind direotion by hour of day, and number of days per month in each direotion class--Continued of SW Wind direction (from) SE ODM OD Aw]A or ronda hat om ojo JHonmwotor ht tH Ot ot ad t ow Oa ato aa do} taonna lo AX AMZ OlO ot a a aq a -oaaann MA AOn MIO oon nn Aly ma Mon ala AY yo aie i Nd a a a a mn daa OOo mI moNonal”d AMaAr-HAlS hr aoanooalr om oamrlo ° AN NG AANA N MI IAM Ae wy i|ro AANA SH Ol ANuanMala ON TMA AIO NDANWO HO ~estoOoN wolW Oot DOAN H/o oFManor]rn It OM a th Haat ola HAMenrwooly NOAM wp wld A 1 1 tm Aad Add Adda iat dadad a Anda MOM oa Ho NOAA oO tlt AARAMOr|+ DwWOt AD O/} tO t+ OM d/o ber] pots Hoo cat] fal) AWONMMA AO PA ela Sh Tr (ie) rF ONM AAI oad mNnNnMA Al “ a 0 i a 3 3 iS = 6 6 ZORUNANM DIO DAOotdm vin dawgonoonr IN OAM~- ODD BIRO NUNMDMO!Y Raspes brs aie aifhe Sin sateie| Ne cca ie ce aes eis igeusiisstice| Se dmmen| je marae lonauna a tI 9 IO ANANA AYA aA Aa a AMNAAMIY Aout t MID DOA ADIN tat mo jo Ar OMM Old st xt nO AYW oO > nmAMWM Oo A> rm AWm Oo a]> COndAAMS COna nae COanaAde OCOn Anne OOnAAMIa tc OD 9 rd +OODA DA Hote ojo Aw©ounonyn WONOHE4 OMmMNN OI wor aan WO 4 did st NAAN Orn UVA WM] I~ ONO WMIO WO AMMM Aw ANNAN A wr nm UVOnD MIM woonont dt StU NA MO] AAA AN EA NVA lO IN AM AN Ml NAA AANA ootr~uno UE UDA AID loa- ow o to ate AMO; jovrt mh Wolo HAM aw tle VGAaddavla Ida daaala dad aAnddala ddddaaala aAovn ono AAD ow +!]y OHOOD +> lo+* HMO Ol maoNn alo aAadAddala A Ao Qi|ro to 09 Hrd tro |ro a cu ad Olu mana dja DAOstD O Mio tmMohr wo mio ODO VY O DID mauot tat I~ DOD N|O tit QU 090 CulCY eo ss fe gwonww +t tit a nS Bed PMC B el sa} Bi g a 3 aloounn ola ln DOO O/H dooonrly lpQmoate Blt dtm std 1 D AD MH Ojo Mm 9D As IPA HOODOO O|O mONNNA Aid Im UAN A Alda a Ada ala ddddaAla Adda Ala AAadAalA monrantel|a xt xt © co @ xt/co ko Hd Aw I]t In doar alo raonnM al ISddd ald ANN aid AMMNMAAIN Ato tN aig NMNMNANIN ronte Mla ONT OD HMO OWOAAND OID wndnnnm alo Oaronddthid oO an ald ANA NAA did a a Coat dAdnvA foal Ino + WO wa lOormarar|a Hthmaaoclo lamoaaala lonanoaly lu cu 9 CCU dadaaaala AAgddaalio awa cla IA ro 1 9 CUCU >| ma oeooo080 lIoacaa00 lInagg000 In DOo000 lIoac00000 SSO000|- ISSoodO|. SSoocgo].- ISSSSG0}- ISSoooO}- ra MYM O Fd] > moOWn oa A> Mm Oq mo dl> mm OAUwW oO dd) > mA UMW O > OOnA AANA jOOnAANIS OORnAANIS OO nAANIS OOAAANIS OMAMNAALIO ID OUNM D | INOMNANOEI|d AYA + cuir ODN Awl AOMNAA tt OU N A HO mam tm nih feds ees Nol ye i - mw oOo No Dw 1 Ico 1AM OM oho lpomdAato loMaaaoly In 0oo Mo O!H Naa dala mmaaadia ou 62 6O Hin rar aa m9 ala doaaala auoown a/m tADOAN OID Ot ONADD UMROD Alt oO OHO VID Od a daaaaa Ald anannala xd Hd qufro qd ddA ID a tt © Jao OA LAO 2 OO — 9 O/H Mm oO MIN Oo ~lin 1p OOM M Ofrd ONNNA Ala Ammo mw we In Om 0 n/oO 19 wo > h {oO tot Ht 0 Oho IO 19 9 wlan AVA R +o lnournmtlo NOH dw oOlW NAA olw g g 3 3 Nada Alea maadaa dia NAaaaw fA NAMA AAA la xt xt 0d ay co] at tot wlo Ko Ht OF O}O AAO tala mt ao oO o|n HMA Io ho tt xt xt 0] mt Hn wo ro] VU ddd I Ad eld att ro xt td tro lo tt OD «| txt th oO xt! ln HA MO MIO out oo ojo WW CODOA|D Od AANA dAadaa tio ddAadaala d daa rr 0 1 MD hwo Hotnnolh jo UO MD O|M HARUNO M+ OADM oO O| DAA ard reer aol ro Hr 0 19 Ito Aan nla mAanaaMmla AQ aia b cs) lu SSS holst] lIocca00 liog0000 iIooo000 loceg000 lona000 ISOGOOG0}:; ISSo000].: essgeeo.: Sseeool,: esssgo. mOdH oO > OU oO 4} > OM wo 4]|> BUH OD d|> OUHOdl> SCOd AAA OOAAANISA SOAAAaIa OCGA AAMe SOddA Aaa Calm 3.5 Le ed 2.8 2.2 4.6 2.4 SW April 2.1 3.0 1.4 May 1.7 4.6 June 2.1 8.6 1.8 6.8 SE August Wind direction (from) 9.0 3.2 5.4 1.4 5.7 1.9 2.9 2.0 cul 6.0 1.6 3.6 1.3 4.9 3.9 3.5 3.3 2.6 1.7 2.6 7.0 2.8 5.8 1.6 1.6 A) 4 1.5 LAKE MINCHUMINA Time of 1500 Av. Av. 0900 0300 1500 2100 Av. 0300 0900 1200 1500 1800 Av. 8 9 1.2 Eo “6 a1 3 aT a9 -6 6 a) 2 2T A) 2.2 S509 wie 8.8 1.4 8.8 1.4 6.3 1.7 6.8 2.1 6.6 1.6 TO: 1.6: Tea 9 8.1 9.0 2.3 eB 221 SW 2.7 6.9 11.8 1.8 Sel Oh Deal ated 2.6 4.3 14.0 1.6 Anle One BLO. O! nee SoG 95.7 (1L.0n-8 3.9 4.4 10.0 2.0 1.3 4.0 Set S21. 1.8 3.6 1.6 3.8 1.6 5.6 3.4 4.7 4.4 2.9 3.7 3.7 1.6 3.8 2atiage.0 4.2 9.4 2rouoee April May June July August 123 SE 6.3 4.6 Wind direction (from) 7.5 3.6 7.4 3,1 122370 4.8 1.4 5.5 1.7 2.7 2.4 1.4 3.1 ney Aeron 3.7 4.3 1.2 4.6 20) Poh 2.6 3.3 a es) 6.9 4.6 3.8 5.6 4.2 4,7 4.8 4.2 5.2 4.8 4 ne 8 poe be} 1.0 ef) 29. 4 2 1.9 1.8 3.1 (a See} 253) 379 2.8 3.8 2.4 3.0 ere seal $.1 2.9 2/9) ae! 6 2 79 1.8 3.4 “4 a KOTZEBUE Tine of 1500 0300 0300 0900 1200 1500 1800 2100 Av. 2100 Av. Av. Av. Av. 3.3 eee. 4,7 2.7 1.7 2.9 6 4.4 3.0 al 4.0 2.8 2.6 1.2 5.5 1.6 3.2 1.7 3.9 1.5 3.1 1.9 4.3 2.1 sw 5.6 Dainese o ely real 3.0 2.6 2.1 2.8 4.8 2.2 6.4 2.0 4.8 April Ma. August Wind direction (from) SE 6.8 4,4 Tl 3.5 Tea 6.7 6.0 6.4 8.1 6.4 6.6 5.4 -8 10.8 7.2 6 A 1.2.1.2 ek Fr ia a i Sea oe See a} 3.4 1.7 1.5 Lz See footnotes at end of table. Av. Av. Av. Av. mued ction class-—Contin wh. dir sach of deys per month in number ection by hour of day, a dir bls 27 .--Wind Wind direction (froc) Ni Cals from) Li @ SW ion Wind direc Calin Wind direction (from) 0300 5 oot June i st O19 19 G8 arial ie 19 © 9 (eee o mano o 91 1200 ~~, Fie alo ou a) 1600 2100 oaoo00 oom a Ii] 2 8 o i) 9 i a} 1 0 oe 1O]IO reat cul @e20000 OO9SGG00 2 yo O rit OO Art et ast nm (2ro=) ti Wind direc fron) ion ( z ind direc W ti direc ind 0500 on (froz) 2800 Weather Bureau coded date 124 254 8-12 13-18 19-24 April Wind velocity, m-.p.h. 4-7 BETTLES Time of Baz 1950-58) 8-12 13-18 19-24 April Wind velocity, m.p-h. (Av. 4-7 9.7 0-3 4.1 BETHEL Time of dey 0300 25+ Table 28.--Wind velocity by hour of day, and number of days per month in each velocity class ae 4.2 5.8 8-12 13-18 19-24 10.7 Wind velocity, m.p.h. April 4-7 9.8 8.3 13.9 4.8 12.4 ath alktyé ANCHORAGE 0300 14.8 0900 1200 Tine 3.7 0900 to -0 -8 4, 3.7 May 8 8.1 11. 1500 0300 4 eat Lei C4 3. 11.0 qas2. May pale 3.7 11.0 1200 1800 0300 0900 1200 ol ol 10.2 9.3 May 4.3 Cy a S27 1500 18600 2100 12.4 Av. 0300 14.6 1.6 68 12.0 ito} a a) a9 ape at ! 4 ict a fa 1800 2100 eile 9.8 oh 2 1 2100 Av. 10. 8. 5.2 8 a) 8 1800 2100. 10.9 6.2 Av. June 6.0 0300 12.0 10.7 June 3. 1235 a alae 0300 0900 June 9.9 AE) a8 8.0 away é =} ral: eb 3.2 10.9 0300 15.8 0900 “ 9 “31200 aleyed 1.0 1200 1500 1800 3. 1200 1500 1800 2100 Av. 1.8 9.8 4.1 1500 1800 far) 10.5 1.0 OST -6 Sie 10.1 8.3 ‘fear allO's 8.2 9.0 10.8 0 3. 200° 12/59 Av. ive) 13.6 Av. 3. 822 4 2.8 July 6.3 aii August 5.9 10.8 9.7 14.0 922 0300 1200 1506 1800 2100 mile 6.2 4. July 11.8 13.4 August 10.7 See CR BEET a sllel are) -6 2.4. 10.9 al 2:2 1200 1800 2100 0900 Av. Ve 3.8 10.7 0300 03900 1200 Fal 2.2 3.7 3.7 Sisal July ihesh 41.2 11.0 8.3 4.2 August 2.6 8.4 7.3 14.6 Deee 11201 3.6" 12.0 6.4 12.0 9.3 922 S114 2100 14.1 0300 17.9 Av. 0900 1200 1500 1800 We 0300 18.6 a “1 1500 «6.0 Ae) 9 10.2 4.2 10.0 2100 ol el ae 50 2.1 79 4.0 6.2 5. 8 Heal 6 9 12.9 Cs aba ale as) -8 6.0 14.4 5.6 13.5 1800" 10-9° 20). 2100 14.7 0900 10 1200 1500 Av. Av. ct TE 9 257 beet 8-12 13-18 19-24 .0 10 Wind velocity, m.p.-h.- A 4-7 0-3 YUKON 03001/3.6 11.3 FT. Time of day 25 8-12 13-18 19-24 ONT April Wind velocity, m.p.h. 4-7 7.9 0-3 FAIRBANKS 0300 16.1 Time of day 267 2.0 3.2 2 2.2 4.2 8-12 13-18 19-24 6.0 Wind velocity, m-.p.h. April 4-7 0-3 9.1 11.4 fag BIG DELTA Time of 0300 0900 1200 1500 1800 2100 day Av. 0900 8.2 0900 14.1 1200 3.1 feel 8 1200 1500 1800 78 6.7 8.1 e iat) 4 ee 2.8 5.7 6.0 8.8 rs) 1.6 tice) 6.8 10.3 He 2.1 1222 June one al 9.2 1 -2 aR 29 Data missing Data missing Ae6. 125 1.3 10.3 1002/ 2 Av. 1200 1500 1800 2100 esi 0300 Av. 2 0900 pal a 1-0 6x2 6.0 9.0 1. May EB June ant 8.2 12.0 9.0 1 0300 13.9 10.1 2100 0900 2100 wit -8 rte! eee <9 2 aE al af Oeil 2.0 1. a) 4.0 6.3 6.2 8.2 May 5.3 ee 9.9 eh June 9.5 foal 9.7 7.8 6.0 10.6 6.7 CRP SERA) Grr ore 3.8 2.4 on. 226 3.8 5.2 0300 1200 1500 1800 2100 Av. 0900 4 3.1 15. 1.4 11,2 0300 0900 15.7 03500 12.9 3.6 25.6 0900 9.6 4.3 16.1 0900 10.7 5.0 14.3 0900 7.8 4.1 18.1 0900 8.1 4.4 17.6 0300 ak 3.6 17.2 0900 «12.2 3.8 15.0 1200 9.8 4.1 16.1 1200 9.0 5.6 15.4 1200 8.1 4.1 17.8 1200 352. 4.4 16.5 1200 2 3.8 16.0 21200 «610.2 4.2 15.6 1500 9.8 4.0 16.2 1500 1-9; 4.3 17.8 1500 8.1 3.8 18.1 1500 9.6 4.4 16.0 1500 ie} 3.6 15.4 1500 8.6 4.1 27.5 1800 10.0 4.1 15.8 1800 8.1 6.2 15.7 1800 8.5 4.8 16.9 1800 8.8 5.6 15.7 1800 atk 3.9 14.9 1800 8.7 4.2 17.2 2100 11.0 3.3 15.7 2100 (15.9 4.5 11.8 2200 11-2 3.1 15.7 2100 10.7 4.1 25.0 2100 we 2.5 15.5 2100. 25.1 $.2 15.8 Av. 10.3 4.1 15.6 AV. 10.7 5.0 14.5 Av. 8.9 Dooce AVA = OMNES baer 6 Oma RAY,= 7 3.5 ~«(lo.8 RY. 10.5 3:8) Los4 Mey May May Mey May May 0S00 8.6 5.0 17.4 0500 8.7 6.0 16.5 0500 6.3 4.1 20.6 0500 6.0 4.6 20.4 0500 9.6 3.0 18.4 0300 8.0 6.2) 2629 0900 8.5 4.7 18.0 0300 6.3 5.8 18.9 0300 5.6 a6) 8 2029) 0900 5.5 6.2 19.4 0300 S50 4.2 ak feel 0900 8.2 5.9 16.9 1200 6.5 6.1 18.6 1200 4. 6.4 20.4 1200 5.4 4.6 20.8 1200 5.0 Lire 18.9 1200 10.4 4.7 15.9 1200 6.2 6.2 168.6 1500 5.4 5.6 20.0 1500 4.1 4.8 eit 1500 4.8 Soe tae 1500 5.8 6.2 19.0 1500 10.4 4.7 15.9 1500 5.35 6.9 18.7 1800 5.6 5.7 2957) 1809 4.4 i29; | 18's7: 1800 5.3 5.0 20.7 1800 6.8 5.6 18.7 1800 22.3 3.6 15.1 1800 6.6 6.4 18.0 2100 8.0 6.5 16.7 2100 Tet 6.8 16.6 2100 t.2 4.7 _19.1 2100 6.2 5.2 19.4 2100 RES 3.7 5 2100 9.2 4.3 17.4 Av. 7.0 5.6 18.4 Av. Pa] 6.5 18.8 Av. 5.8 4.7 20.5 Av. 5.9 5.8 19.3 Av. 10.7 4.0 3 Av. Te 6.0 17.8 June June June June June June 0300 5.5 7.0 LT 0300 7.6 5.2 17.2 0500 6.35 4.6 19.1 03500 3.7 4.2 20.1 0300 6.6 378 5 0300 5.8 6.0 18.2 os00 6.4 6.0 17.6 0900 6.7 7.3 16.0 0900 5.9 5.1 19.0 0900 5.2 4.8 20.0 0900 Kare 4.3 5 03900 6.2 529)” 2729 1200 aS. eat) 1ok2 1200 5.6 6.2 18.2 1200 6.2 4.3 19.4 1200 4.9 5.6) 19.6 2200 8.3 4.4 +5 1200 4.8 6.8 18.4 1500 3.8 636 19.7 1500 4.0 6.3 19.7 1500 6.2 5.4 18.5 1500 5.6 6.3 18.1 21500 97. 5.0 2 1500 3.0 G-Seo a! 1800 3.6 6.7 19.8 1800 5.0 6.8 18.2 18600 7.35 i ea er 1800 5.6 6.8 17.7 1800 3.3 4.4 2 1800 3.4 6.4 20.1 2100 4.6 6.8 18.4 2100 5.8 6.9 i7.3 2100 7.6 4.7__17.8 2100 4.7 7.0 18.5 2100 8.2 4.8 79 2100 4.7 5.0. 20.2 Av. 4.8 6.5 18.7 Av. 5.8 6.4 17.8 Av. 6.6 4.9 16.5 Av 5.2 5.8 19.0 Av. 8.2 4.5 .3 Av. 4.6 6.2 19-2 July July July July July July. 0300 4.5 5.0 21.5 0300 8.6 4.9 17.6 0300 8.7 4.1 18.2 0300 5.8 3.9 22.3 0300 3.9 $.0 24.1 0300 4.7 19.8 0900 4.2 5.4 21.4 0300 t.9 5.0 18.2 og900 8.2 5.2 FLT.7 os00 5.0 3.7 22.3 03900 4.2 2a, 24.77) os00 S.2 20.9 1200 4.0 5.2 21.8 1200 6.2 6.8 18.0 1200 7.6 5.7 17.8 1200 4.3 4.8 21.9 1200 5.8 4.5 20.9 1200 4.8 20.7 1500 4.0 Se0ne ote 1500 5.7 ices 18.2 1500 8.9 5.0 Lier 1500 5.8 5.4 19.6 1500 6.2 5.1 19.7 1500 5.4 20.7 1800 3.4 6.2) (2154 1800 5.0 5.8 20.2 1800 8.0 5.0 17.9 1500 6.2 5.8 19.0 1800 6.1 4.4 20.5 1800 5.9 20.2 2100 4.2 SeSim elak 2100 7.6 4.7 18.8 2100 8.8 5.5 16.8 2100 5.4 6.2 19.5 2100 6.2 Su7e 22 2100 6.0 19.7 Av. 4.0 Sone to} Av. 6.8 5.7 18.5 av. 8.4 5.0 17.6 Av. 5.4 5 20.6 Av 5.4 he peer ote Av. $.0 20.5 August August August August August August 0300 4.0 3.8 3.2 0300 7.5 5.8 Lio) 0300 6.9 2.4 $2207 0300 5.35 3.0 22.7 0500 3.4 2.0 25.6 0300 $24 21-8 0900 3.0 3.0 ie) 0900 6.8 4.6 19.7 03900 5.7 4.6 20.8 0900 2.8 4.4 235.8 0900 3.4 2.0 25.6 0900 3.3 23.8 1200 2.4 3.0 6 1200 6.1 5.8 19.1 1200 5.4 4.4 21.1 1200 a9: 5.3 25.8 1200 5.0 CEs earl 1200 4.0 25.8 1500 1.9 3.9 ia 1500 6.6 5.7 18.8 1500 5.0 4.8 21.2 1500 2.6 6.4 22.0 1500 3.9 4.0 23.1 2500 4.3 235.9 1800 2.8 4.2 ie) 1800 6.1 6.1 18.8 1800 6.1 O28) ele 1800 229 6.1 22.0 1800. 4.7 3.2 23.1 1800 5.5 22.4 2100 3.0 4.8 25.2 2100 8.2 6.2 16.6 2100 7.0 5.0 19.0 2100 3.5 5.7% 22.0 2100 4.2 3.5 4 2100 . 4.2 22.4 Av. 2.8 3.8 74 Av. 6.8 Stinleed Av. GOmun accu COs Olen. leAMis 3.1 Seaeeas Av. a ass Av. 2 4.1 23.0 ST EE a Ce as ee ee ee ee 128 Table 29.--Amount of cloud cover by hour of day, and number of days per month in each cover class--Continued (Av. 1950-58) McGRATH NAKNEK NORTHWAY SUMMIT TANANA UNALAKLEET ne Cloud cover (tenths) ae Cloud cover (tenths) id Cloud cover (tenths) ee Cloud cover (tenths) as Cloud cover (tenths) ane Cloud cover (tenths) day 0-3 ~=«4-7~SC«-10.—St—éhny 0-3 4-7 8-10 day 0-3 4-7 ~~8-10 day 0-3 4-7 ~—«8-10—S day 0-3 4-7 ~=—«8-10_—Ss day 0-3 4-7 ~—«8-10 April April April April April April 0300 10.7 3.6 15.8 0500 10.2 3.2 16.6 0300 8.4 4.6 IezS) 0300 11.3 4.3 14.3 0500 13.7 5.1 11.2 0300 10.4 3.4 16.1 0900 9.6 4.6 15.9 03900 6.7 3.9 19.4 0900 8.6 4.7 16.8 0900 9.9 3.7 16.4 0900 Leo: 5.7 12.4 0900 7.8 4.4 fart, 1200 9.7 4.2 16.1 1200 6.1 3.8 20.1 1200 7.3 5.4 17.2 1200 9.7 3.3 LTO 1200 W251 4.8 13.1 1200 8.3 5.1 16.6 1500 8.6 5.4 16.0 1500 5.2 5.6 19.2 1500 Misc 5.5 17.6 1500 7.4 4.8 17.8 1500 10.9 4.9 14.1 1500 9.8 3.8 16.5 1800 8.6 4.6 16.9 1800 6.9 4.4 18.7 1800 6.9 5.3 17.8 1800 8.2 5.1 16.8 1800 10.6 6.4 13.0 1800 8.9 4.1 17.2 2100 ll.1 4.1 14.8 2100 9.8 4.6 naa 2100 EOI 4.1 15.8 2100 (10.3 4.3 15.3 2100 14.2 4.8 mete! 2100 10.8 4.6 14.7 Av. CG 4.4 15.9 Av. 7.5 4.2 18.3 Av. 65a 4.9 17.0 Av. 9.5 4.2 16.3 Av. 12.2 5.3 12.5 Av. 9.3 4,2 16.5 Mey _ May May May May Nay 0300 Te Gyeat 18.7 0300 5.3 4arL -6 0300 3.8 7.0 20.2 0300 faa 3.7 = ©=620.1 0300 10.9 6.8 13.6 0300 1.9 5.1 18.0 03900 7.8 4.2 19.0 0900 3.3 3.3 3 0900 ar 6.2 20.7 0900 Gant 4.6 19.8 0900 oe2 6.2 15.7 03900 8.7 5.0 17.3 1206 5.4 29 Se eO il, 1200 2.35 5.4 <2 1200 2.8 S29 22'3 1200 5.3 7.6 18.0 1200 TL 7.6 16.3 1200 7.4 5.9 177 1500 4.3 5.9 20.8 1500 2.0 4.9 sal 1500 2.3 4.7 24.0 1500 5.4 6.2 19.3 1500 5.9 8.3 16.8 1500 6.9 6.2 L7.9 1800 5.2 5.1 20.7 1800 3.0 5.7 .3 1800 3.6 4.9 22.6 1800 6.1 6.2 18.7 1800 7.8 5.4 17.8 1800 Tol 6.2 17.7 2100 7.5 4.4 ngs 2100 3.1 7.6 at 2100 5.0 5.6 2054 2100 eh 5.2 18.0 2100 9.0 7.4 14.6 2100 8.2 5.4 17.3 AVA ROLC DEA CIN@LOTS & AVs; © Gs2 Sse e@2.65 AV, 3.6 Sal ebay Av. 6.4 5.6 19.0 AV. 8.0 6.9 15.8 AV. Ts See 4 June June June June June June 0300 5.1 AM TUSteO. 2 0300 3.3 4.3 .3 0300 3.6 Bes Nee g: 0300 4.6 3.9 21.6 0300 Tal 8.3 14.6 0300 5.3 4.6 20.1 0900 5.3 S29F #2078 0900 O57. 4.0 3 0900 4.8 §.3 19.9 0900 4,0 3.9 22.1 0900 6.7 8.35 15.0 0900 5.4 5.6 19.0 1200 4.1 5.1 20.8 1200 3.1 3.7 Jc) 1200 3.2 7.3 9. 1200 2.8 4.9 22.3 1200 4.8 8.2 aby Ate} 1200 5.4 6.2 18.3 1500 3.7 4.8 21.6 1500 2:9 5.4 ith 1500 2.9: 5.0) 322.5 1500 3.3 5.8 20.9 1500 3.2 ao) 16.6 1500 5.7 6.2 18.1 1800 3.7 5.6 20.6 1800 3.6 ae <2 1800 3.1 Del. eels 1800 3.3 6.7 20.0 1800 4.7 8.7 Gay, 1800 5.4 6.6 18.0 2100 5.3 4.6 20.1 2100 3.8 4.9 -3 2100 ape aii eee 2100 4.2 5.3 20.4 2100 5.0 8.6 16.5 2100 5.7 5.3 19.0 Av. 4.5 4.8 20.7 Ave 3.2 4.6 aa Av. 3.4 Soe, les Av. 37 5.1 21.2 Av. 5.2 8.7 16.1 , Av. 5.5 5.8 18.7 July July July July July July 0300 4.6 3.8 22.7 0300 2.8 5.0 25.2 0300 3.4 Sav) “2be8: 0300 5.7 Stay 221 0300 8.2 4.3 18.4 0300 3.3 5.7 22.0 0900 5.9 Oe Oi 216 0900 3.3 252) 25.4 0900 4.9 6.4 19.7 0900 5.1 3.2 22.6 0900 6.2 6.4 18.3 0900 3.2 4.8 23.0 1200 4.2 5.0) °21.8 1200 3.2 3.4 24.3 1200 4.3 6.4 20.2 1200 4.4 4.9 21.7 1200 4.7 6.8 19.6 1200 3.7 6.1 21.2 1500 3.7 5.1 22.2 1500 2.9 4.2 23.9 1500 3.3 7.3 20.3 1500 4.1 Din ele 1500 4.2 6.0 20.8 1500 4.2 6.6 20.2 1800 4.3 3.4 23.2 1800 3.1 5.0 22.9 1800 4.2 ber! 20.9 1800 5.0 4.0 22.0 1800 eet) fale 20.0 1800 4.1 6.0 20.9 2100 4.3 Onfseees.0 2100 3.4 4.2 23.3 2100 4.8 5.5: 20.9 2100 6.3 3.7 20.9 2100 4.6 anek 19.3 2100 3.9 5.9.8 2152 Av. 4.5 eee Av. 3.1 3.7 © ©624.2 Av. 4.2 6.2 20.6 Av. 5.1 4.1 21.8 Av. 5.3 6.35 19.4 Av. 3.7 5399 2ls4 August August August August August August 0300 Chae Onlin eae 0300 3.5 2.8 24,9 0300 4,4 4.6 22.0 0300 4.2 4.1. 22.7 0300 5.2 3.8 22.0 0300 3.0 3.1 24,9 0900 3.0 USS 26s 0900 2.0 1.6 27.4 0900 4.6 4.8 21.6 0900 2.9 2.9 25.2 0900 3.4 Oo4. 2252 0900 2.7, O21 25.2 1200 Zot 3.8 25.0 1200 1.4 3.6 26.0 1200 3.4 6.1 21.5 1200 2.6 4.0 24.4 1200 3.1 5.4 22.4 1200 2.4 3.4 25.1 1500 Nist/ 3.4 (25.9 1500 pleal 4.3 25.6 1500 raph tee 2156 1500 3.0 3.1 24.9 1500 2.3 5.4 23.2 1500 2.4 3.4 25,1 1800 3.6 3.4 24.0 1800 2.1 4.9 24,0 1800 3.2 626); £212 1800 3.1 3.7 24.2 1800 3.8 6.0 21.3 1800 2.4 3.4 25.1 2100 4.0 3.6 23.4 2100 2.4 4.9 23.7 2100 5.2 5.9 19.9 2100 4.8 3.3 22.9 2100 6.1 4.1 20.8 2100 3.2 3.8 24,0 Av 3.0 3.2 24.8 Av. 2:20: o.7) 2513 Av. 3.8 5.97 eels Av. 5.4 3.5 24.1 Av. 4.0 5.0 22.0 Av. ZiT 3.4 24.9 Source: United States Weather Bureau coded data. 129 Table 30.--Visibility distance by hour of day, and number of deys per month in each distance class (Av. 1950-58) ANCHORAGE Time Visibility in miles Visibility in miles n of 0- 3/16 nml/o= alae oa Fil ayes abe is ° T 3 day 1/8 _-3/8 3/4 2-1/2. 46 T+ dey i/s_-3/a__ 3/4 2-1/2 6 T+ day _if/e -3/8 3/4 2-1/2 6 as April April April 0300 Osi OL) 0.8 0.7 28.3 0300 0.2 LifimnselGeneo sO 810500: 0.4 O:Bie ea 0900 2 fameale 28.4 0900 0.2 ney 1.3. 2.4 26.0 0900 2 8 1.0 28.0 1200 pal RS oO, 28.6 1200 .2 28). SUG 27-45 keOo 0.1 Ail ce ies ay. 1500 -4 = 1.0 28.6 1500 2 Pi: ene 1: ee 110, 0) au! aS noe Teen 1800 <8) a 28.8 1800 2 aye Alar ie rare TUGeT0) 2 1.0 292m 9 2100 comet 29.3 2100 -2. 3 9 2.1 26.5 2100 hi -8. 28.5 ve =o! eer 28.6 Av. v1 me oie srasch Oe 2 Bose fee Sn: May May Mey 0300 aa = 30.8 0300 0.3 a 2 6 79 28.6 03500 0.2 Eal = 6 23 29.6 0900 eal 30.9 0900 pal 160, LoS 29204 0900 2 eS -7 29.8 1200 31.0 1200 2 -7 30.1 1200 ath 2 2) 30.5 1500 31.0 1500 ae} -7 30.0 1500 As oes 1800 rae 30.9 1800 ls -4 30.5 1800 =i 2 SONG: 2100 2 30.8 2100 Ail mal -6 30.2 2100 el 2 Sv s0-5 Av. aD 30.9 Av. 1 ee “i 25 Sremeoan! wAVE al aK TSEcOLS June June June 0300 (0.1 2 9 28.8 0300 2 a Bi -4. +«21-7 26.5 0300 1.6 28.4 03900 8 29.2 0900 TEOas920 27 0900) =lget omOBsG 1200 3 29.7 1200 4 -8 28.8 1200 .2 Sth Aca 1500 roe yt 29.7 1500 2 -T 29.1 1500 =i, cal -8 29.0 1800 2 (29*8 £1800) -8 29.2 1800 -4 29.6 2100 4 29.6 2100 22 -4 29.4 2100 ok ee) Av 5 29.5 Av. ay Bal Papen POLO AVE 5 1.0 28.9 July July July 0300 a 1 Tolar esse; 0S00 enh a a Pidigg oad ress)» 0800 12 2 +2 TS vag les ed re 0900 41.2 29.4 0900 sl: 2.1 2.7 26.1 0900 +4 TOM Lo Samet 1200 Su 133 29.4 1200 -9° 2.0 28.1 1200 ol 2 +3 2.5 28.2 1500 3 1.0 29.8 1500 -8 1.6 28.6 1500 -2 othe Bere Ahr 1800 a CT: 29.8 1800 -7 1.9 28.4 1800 2 -4 2.0 28.4 2100 als 31.6 29.0 2100 1.1 1.7 28.2 2100 5 : 2.5 27.8 Av. zat Analy 29.4 Av. aul al Dias aoiae. tke 2 “1 -8 1.9. 28.0 August August August 0300 ae 72 sop rLsO 29.3 0300 ae Alien Vs 9 ase Sin e2nn | 0500; 2 a] i) 1.0 3.4 25.8 0300 sa 152 29.4 0900 .2 4.4 3.6 22.8 0900 a +2 1.4 2.8 26.5 1200 Ral WE.) 30.1 1200 1.6 4.2 25.2 1200 ot -7 2.0 28.2 1500 ar 30.3 1500 -9 3.8 26.3 1500 -T 2.1 28.2 1800 2 eal ee 30.4 1800 pla enh olsoae velle2) +2 +6 1.5 28.6 2100 1.2 29.8 2100 zy Tec emcee wenr 2100 +8 2.0 28.2 Av. Ba at Seng, 29.8 Av. T ms 2 22 OMROnT Av. at a al +8 2.3 27.6 BIG DELTA FAIRBANKS FT. YUKON Time 3 i i Time Visibility in miles Time Visibility in miles of 0- = of 0- 3/i6 1/2= «1 - = of 0 3/16 je a day 1/8 T+ aay U/B.) 6=3/8e 23 /SUn Seo 6 T+ day 1/8 _-3/8 «3/4 2-1/2 6 T+ April April 03500 0.7 0-7 28.6 0300 0.2 1.5 28.6 0300 0-2 0.9 0.6 27.3 0300 6 1.4 28.0 0900 0-1 1.2~ 28.7 0900 6 AT COUT, 1200 ar -4 29.2 1200 a1 -4 29.5 1200 4 1.0 28.6 1500 13 3 29 1500 42 02958) 2500 a :7 28.9 1800 -6 -2 29.2 1800 ait .2 29.7 18002/ a5 26) 127:9 2100 0.1 ae) -6 29.0 2100 aul -4 29.5 22001/ 0-1 ale <9 27.3 Av. BF 6 28.9 Av. mal 76 29.5 Av. .6 28 mooed: May May May 0300 4 71 «30.5 +=0300 sos A 72 30-2 0300 .3 =7 30.0 0900 oe 30.7 0900 te -4 30.4 0900 -6 27) M2Be 7 1200 ae -1 30.7 1200 ',4 30.6 1200 eal =6) S0:3 15002/ al = 30.4) 500 33) “3057 9 S500 a 230) S0EG 1800 2 30.8 1800 -4 30.6 - 18002/ fas 500 2100 ast +2 30.5 2100 -2 30.8 2100 -4 E2989 Av. 5) AIS s0s6 | AVE pe 735 00LG AVs 3 -6 29.9 June June June 0300 0.1 74 «29.5 0300 ae 79 29.0 0300 ou ae aeee 0300 42: -8 29.0 0900 -7 29.3 0900 ait Pee ouaai 1200 -8 29.2 1200 eal +3 29.6 1200 395 2981) 1500 ol sBy eeScdem. 2500. ail ~.-)29-6) — 1500 1.0 29.0 1800 -3 29.7 1800 +9 29.1 1800 1.4 28.6 2100 0.1 ron eon. | 2100) 120 VON 228.8 C1O0N a 1, Qos a Av. Ee FOR SeotAn /AVS aa Be, ENG ale ae) July July July 0300 au Bre aT 1.6 28.5 0300 0.4 ao 4 Zoe Lue eeso) SOsOUmmOnt 4 a .6 PiSMMeess. 0900 4 -9 29.7 0900 eal 2 -9 1.8 28.0 0900 a5) a eG) 2 Opene7e5: 1200 2 -9 29.9 1200 ak as) 2 1:0 29.4 1200 gil .2 =3 wi) 26) 128el 1500 Bil -8 30.1 1500 cal ppt Se ers ABST aI) ql ort 2 BE) a aS 1800 3 1.1 29.6 1800 2 $2) 1123). 29235800, 2 4 2 17 | 2877 2100 <6 1.0 29.4 2100 2 -2 1.8 28.8 2100 “al -6 Sr Meneses PEs Av. 4 TLyeosl AVE at =a = Pipe Lee ice Bay 2 2 6 sey egies August August August 0300 BT mal 2 77 29.9 0300 aD 4 1.3 2.1 26.9 0300 a 72 aul Some SOE 0900 Bl <1 1.7 29.1 0900 a -8 1.1 1.6 27.4 0900 ea) 7, BOLSieer-& 1200 aft -3 30.6 1200 is 28) U3) 929-0) 200 au al -3 1.6 28.9 1500 or -7 30.2 1500 Fal “3 -9 29.7 1500 4 TE en ELS} 1800 ay -3 30.6 1800 pal 22) 710) 2928718 A800 ot -6) 30.5 2100 aa -8 30.1 2100 au Ss -8 29.8 2100 oT -2 22) 1.4 29.1 Av. ze SSpRSONL Avis Re oa umes © Lars au = ine slg Le) See footnote at end of table. = 130 Table 30.--Visibility distance by hour of day, and number of days per month in sach distance class--Continued fd 7aRN-#R) GALENA GULKANA HOMER Time Visibility in miles Time Visibility in miles Time Visibility in miles of os S)iGomajes a = oe of 0- Sls) dje= = one of 0- 3/fl6 1/2- 1 - 3 - da. 1/8 -3/8 3/4 2-1/2 6 T+ day 1/8 -3/8_ 3/4 2-1/2 6 T+ day 1/8 -3/8 3/4 2-1/2 6 T+ April April April 0300 0.1 0.6 1.4 eTs9 0300 0.6 0.4 29.0 0300 0.1 0.1 0.2 1.0 1.1 27.5 0900 Ost 220° 2.2 (27.38 10900 2 2 29.6 0900 1 +3 6 1.2 27.8 1200 =e -6 .7 28.5 1200 4 -2 29.4 1200 nal if 7 28.5 1500 1 ne) -7 29.0 1500 2 29.8 1500 1.1 -9 28.0 1800 7-6 «A «29,0 1800 2 -1 29.7 1800 4 9 28.7 2100 -8 8 28.4 2100 2 4 29.4 2100 2 1 2 :7 8 28.0 Av. 1 -6 9 28.4 Av. 3 2 29.5 Av. 1 aI a if 9 28.1 May May May 0300 0.1 -4 “2 30.3 0300 ar a 30.7 0300 1 e aE 4 50.2 0900 pul Ar 3 30.4 0900 O21 ol ac 30.6 0900 4 50.5 1200 2 .1 30.7 1200 or aa +1 30.7 +1200 1 2 30.7 1500 le ae 30.7 1500 2 30.8 1500 al 30.9 1800 eal “2 30.7 1800 1 30.9 1800 ok -s059 2100 +341 30.6 = 2100 +1 30.9 2100 1 30.9 Av. ol we. a 30.6 Av. ape eal 30.8 Av. 2 30,7 June June June 0300 mal ok “6:9 29 28.7 '0300'2/\021 0.3 -6 27,0 0300 2 3 at 6 2 28.9 0900 Fede le) 28.4 0900 ol 29.9 0900 3 ppt 29.6 1200 4 a) PASE 1200 30.0 1200 1 x) 29.6 1500 ob 1S af 28.9, 1500 30.0 1500 +1 29.9 1800 +2 ao) 20 28.5 1800 30.0 1800 72 29.8 2100 wilt 728i 2859 200 30.0 2100 1 2429.5 Av. =a 73 9 28.7 Av. a ie Oba AY. 1 L 2 29.6 July July July 0300 4 75 ne a) EC) 0300 ol ai a) -2 -6 29.9 0300 6 3 2 1.2 28.7 0900 -6 Lele div6: 277 1.0900 pal 6 30.3 0900 pel 3 6 30.0 1200 75 10 36° 328.9 _ 1200 6 30.4 1200 4 30.6 1500 A 12) LA 28.0 1500 ol 4 30.5 1500 28 3 50.4 1800 a 4 -6 1.5 28.4 1800 eal -7 30.2 1800 3 G6 30.1 2100 ak -4 ne OumliG 279° 2100 ol -8 30.1 2100 Pe 3 8 29.8 Av. 3 3 DOM 1. Se S2SL Aye ai 6 30.2 Av. 1 va 2 T 29.9) August August August 0300 ear a TGP 292 0300: a 3 1 i] 3 29.8 0300 6 3 6 3 8 28.4 0900 a 4, 1.6 28.9 0900 1 ol 3 30.5 0900 al 1 ol 1 7 29.9 1200 me) 8 29.3 1200 eL 30.9 1200 1 1 3 30.5 1500 5 36) 172929" “1500 av 30.9 1500 3 -4 30.3 1800 4 .2 30.4 1800 1 30.9 1800 2 1 -6 30.1 2100 4 1.2 29.4 2100 2 30.8 2100 a1 1 3 2 6 29.7 Av Dam O NM: OSS ya Avis 1 =) 2 30.6 Av 1 1 2 2 -6 29.8 _ ILIAMNA KOTZEBUE LAKE MINCHUMINA Time Visibility in miles Time Visibility in wiles Time Visibility in miles of 0- S/lG=a/ = aa he of 0- 36 Uj2- 1-- TS of 0- 3/l6wad/e= l= oa day 1/8 _-3/8 3/4 2-1/2 6 T+ day 1/8 _-3/8 3/4 2-1/2 6 T+ day 1/8 -3/8 3/4 2-1/2 6 T+ April April April 0300 0.2 0.2 0.9 ean 26.6 0300 o.1 0.3 ONT. U2) ..2.9 24.8 0300 0.1 0.2 0.4 Ong 28.5 0900 cal 4 at 1.3 27.4 0900 .2 2 Tak Tee 258 one, 0900 A 9 28.9 1200 al uy -8 -9 28.1 1200 ee “2 a V8) 14 Oni 1200 ne aye 29.1 1500 0.1 4 6 alent 27.8 1500 4 ae) 1.4 1.4 25n9 1500 a 6 29.3 1800 ols 4 1.5 -8 27.4 1800 3 “4 a Wes ee AAS 26.6 1800 2 4 29.4 2100 wl el -4 line 1L2ee 2720! F200 3 -6 1.7,°1.8 25.6 2100 au «2 29.0 Av. alt ma 3 9 1.2 27.4 Av. aa 3 Bie VEAL Oy ee5c7 AV 5 ere May May May 0300 ol! pl apt -8 ad 29.2 0300 A 4 no aces) 27.5 0300 0.2 alk ep ae 6 29.8 0900 ie A 30.1 0900 ol +2 4 14 1,3 27.6 0900 4 30.6 1200 ab ve 14 30.3 1200 -1 “ib ny pls eae) 28.5 1200 a ab 30.8 1500 Eat 1 -3 30.5 1500 +3 72 7 29.8 1500 el 222) S07 1800 oe sul 30.7 1800 ne +2 4 4 29.8 1800 23 30.7 2100 ce ate 30.4 2100 eal ne 4 8 4 29.1 2100 4 30.6 Av. pee 3 4 30.2 Av. 2: a2 4 8 a:) 28.7 Av. ok a! 30.6 June June June 0300 a] od i) +6 -6 28.2 0300 af aL 14 1.1.6 27.1 0300 Bia ed ao i 0900 oak +3 8 28.8 0900 al wa. 4 6 oT. 27.1 0900 <2 dx} 28.9 1200 pal -3 29.6 1200 el a) de 6) 27.8) 1200 Fal nce Ore 1500 alt Ere) 1500 ol Ae} +3 fe) 4 28.1 1500 ai} 29.4 1800 -3 29.7 1800 4 ak +6 -6 .3 28.0 1800 12, 329.8 2100 -6 29.4 2100 2 6 8 6: 4.7 27.1. 2200 mOLe Leone: Av 1 2 4 29.3 Av +3 72 5 a0 Sime e700. Av. ol Oe Son July : July _ July 0300 ee 4 8 BYE 2.2 25.7 0300 4 2: oe 1.3 1.2 27.6 0300 4 ol el -3 2.1 28.0 0900 oak “4 aR) 2.0 27.6 0900 =; ott -8 1.2 28.1 0900 i ee GABAA as sreh heal 1200 aa 5 162 29.4 1200 ar 20 8 29.0 1200 ads el 1.0 2956. 1500 at ia 1.1 28.7 1500 set fy 129% 29.0) 1500 a) met) oO ed! 1800 oul 4 1.0 29.5 1800 1 pd 2 cong lat ac oer es SLCO0, +3 7 30.0 2100 sak ak rie 8 29.3 2100 ne atk ah -8 mth 29.1 2100 al 22 all 30.0 Av. el. al aed 8 1.4 28.4 Av. =: ol -3 -8 1.0 2seT. Av ae at Eyes almab 29.5 August August August 0300 at -2 3 158 3.1 2575: 0300 ae aut 3 8 2.2 27.4 0300 el 2 .6 6 29.5 0900 1.3 Lag, 27.8 0900 re 1:0, 2.0 27.8 0900 ak ol «4 30.4 1200 ol 2] ee 28.8 1200 onl CM erat) 27.6 1200 al. .2 6 30.1 1500 at pak ale 1.9 27.8 1500 2 -4°1.9 28.5 1500 rae +1 30.8 1800 “a iO) “9 1.4 28.3 1800 +4 6 1.4 28.6 1800 a ail; 30.1 2100 eile +3 1.4 rk 28 2100 rt ale 28.8 2100 oe 30.3 Av. aul 72 ne But} OTE. Av. 22 1 28.2 Av. ma 2 5 30.2 * See footnote at end of table. 131 Table 30.--Visibility distance by hour of dey, and number of deys per month in each distance class~-Continued {hw 1AKN_5R) McGRATH NORTHWAY Time Visibility in miles Time Visibility in nijes of 0- Ey Ate ae el = oe of 0- 3/16 (-/2- = sr aay 1/e__-3/8 3/4 2-1/2 6 T+ 6 74. day 2/s- -3/e 3/4 e-1/2 6 T+ April Apri April 0300 0.1 0-8 0-6 28.3 0300 0.2 0.2 0.4 V1 268) T25s5 ~~ 03005 Fo: 0-2 0.1 OLD -umenee 0900 pal -8 1.1 28.0 0900 ail a Be) fete) 56ts)) 20900 =3 e835) (2826 1200 eal P6acdy Pee 1200. 3 <8) el Bigs 27 te elec ou oid. Sth eee AES 1500 a2 26) 1:0) ¥2s.2.- 3500 <2 we “Gia Ye7ee) 500) fin Seok: 1800 za! 23) 8 _ 2828) = 71600. 4 are -6 27.8 1800 “1 ea <3 ed) 2982 2100 2 PAU Gae 282) 2100 eal 3 Uae 27a 2100 a2 ae = 7 Av. Parl SS NOM eats: Wawn ell =o iE ey preg = Ea a -6 .5 28.8 Mey Mey Mev 0300°—«o-2 0.1 aly atemsono, (0300, 76 ag 76 +7 2.0 26.4 0300 ee ai [6m OMmmeos2 0900 etl .8 29.6 August August August 0300 ai 2 1.1 2.4 27.2 0300 i) 1207 aes 2.2 4.8 20.9 0500 +4 +2 5 -4 .8 28.7 0900 val -9 2.1 27.9 0900 ail 250. 2Snyi e512) 0900 only SC 1200 Ea (i pale ppt STPAfoYe) 13. 329" 2778) 2200 2 264 S052: 1500 s2 des) 2955) 99500; 2S: 1222) 22775) i500 -8 30.2 1800 -3 1.7 29.0 1800 os -8 2.1 27.8 1800 oe a es 2100 =9 1.6. 28.5 2100 aul “5 1.5 2.6 26.7 2100 8 30.2 Av. ar ~6ae8) webes "Avs ae = ) Vom s9ouee6rO! | Av. a aw 2 .8 29.8 SUMOT TANANA UNALAKLEET Time Visibility in miles Time Visibility in miles Tine i of o= 3/6 —-1/2= D= 3 of 0- 3/i6 “1/2- si 3 - of o= r 3= day 1/8 _-3/8 3/4 2-1/2 6 TH day 1/8 -3/8 3/4 2-1/2 6 7+ day 1/8 2 6 ue April April 0300 0-2 1.6 1.6 26.6 0300 Orciataimeseee6; (OS0Dmros 4 ied pNOCommeTaL 0900 s65 isa, “i28e0° 30900 0.1 .3°* .8-~2828 0900 zu, 23 EE 1. TOTES 1200 -8 1.0 28.2 1200 et t2°"a0) -28t7) 1200 An a AS -6 -6 28.3 1500 0.1 1 £9) dled) 42728) 91500) at .150% p 27.9)" 91500 2 -6 -9 28.3 1800 cB -4 1.4 28.0 1800 -4 29.6 1800 aa al suk 1.0 +5 28.5 2100 al ESO Seer oe gelog: WULIeES APeSeG 2700 4 4 NS Ome Te9 Av. 2 Bp dvietan Ave 720] By 29k0) Ave a 22 =D 8 78 27.9 May Nay May 0300 0.1 zal 3 1.4 1.4 27.4 0300 0.1 ali Tol aay mesOrL 0300 2 -5 UF Olea ONES ES) 0s00 sil! -8 1.0 29.7 0900 sl 9828) ©3508. Voso0 2 at 2.53 «21-0 28:4 1200 pal 4 -7 29.5 1200 tf) S0*S wt e00. = 4 -6 29.9 1500 .9 -3 29.8 1500 «t, 22") 3057, 500 2 -8 Ser Lif 1800 4 up 8 29.6 1800 ail! 3 30.6 1800 a) =e ae el Se AES 2100 As eSiwed eOOVo ne LO0, eS S7S0F6) BELO: =o 2 4 -4 1 29.6 Av. 12 18 .9 29.1 Av. S12; esi SOlS) WAWS a 22 2 S17 -6 29.2 June June June 0300 52 z9 76 28.5 0300 a: 72 1.4 28.5 0300 2 ES =3 Us Olea Ommeoreo 0300 aa +3 29.6 0900 aL el or) 26st. OS00 pat ail oi 8 au ee 1200 od! -1 29.8 1200 22) V2) $2826; 4200) ot .3 a) -6 28.2 1500 4 29.6 1500 o£ 2577-22629) $1500) git cal 2 .3 -7 28.6 1800 -6 29,4 1800 ol -1 > .9. 2859° 1800 cal 2 2 ah EY 2100 2 «729.1 2100 ea! slew egto) FeTOO a2, cal 2 sf sine Bea Av. ze 3 29.5 «AV. ail tau dedpm 2ee6) Ave eal aa! 22 8 76 28.2 July July July 0300 a2: z9 6 TES Met Oro hos rD 03500 Sat, aul! 2.2 1.3 28.35 0300 zal =o soi, bri 0300 al laa) §29%e- 90900 4 39 e822 eg BO900 <0) 6) 528-6) 1200 -9 30.1 1200 4 -7 2.1 27.8 1200 a eS AS 1500 at “7 302 1500 aS 9 .9 28:9 1500 aul aul -6 ESeotS 1800 22) 91.3) “2975, 91800 -3 -6 1.7 28.4 1800 2 1 6 Pome 2100 aut «41.6 28.9 2100 2 -6 1.6 28.6 2100 2 orf eee) Av. .2 a 34 1.4 28.9 Av. -3 -8 25652823 “Ave git =a) atl a bs} August August August 0300 7) a7, 1.2 2.1 26.8 0300 7) 0.2 es TOjec SST Ae OSOD 53 i ys eee 0900 a .2 1.1 29.6 0900 ail 2 -7 2.6 27.4 0900 sat Vey alge a0) 1200 a 2 9 29.8 1200 1 -6 1.4 28.9 1200 sak cals) ES 1500 1.1 29.9 1500 sa ta ye9te" “i500 eq) = do) gare ES 1800 1 -2 21.1 29.6 1800 -3 30.7 1800 ail 39) eS. (Bry, 2100 .6 2.2 28.2 2100 +1 1.3. 29.6 2100 mi aD 1.3) 1.0. 2874 Av. a: T 4 4 29.0 Av. aul 34s) 29.0 Av. aa! 1.1 Te QS 1/ Minor data discrepancy Source: United States Weather Bureau coded date. 132 we © _ . ; } | | | | Fi Table 31.--Height of ceiling by hour of day, and number of days per month in each height class 1950-58) (Av. BETHEL Time of ANCHORAGE Time of Ceiling in hundreds of feet Ceiling in hundreds of fest 50-95 96-199 Unlin. 30-49 April 30-49 50-95 10-19 20-29 April 5-9 3-4 1-2 0 da: 3.2 2.7 1.8 14.0 3.1 0300 0900 1200 1500 1800 2100 Av. LaST 0.4 0.1 0300 0900 12.7 1.8 15.8 0.2 12.2: 2.7 15.5 8.4 1200 CHL 12.8 8 2.5 14.6 1.3 1500 13.2 14.0 2.0 1800 2.8 i) uN 13.6 2100 Av. 2.2 2.8 14.7 May May dh wo mow nua and moh © ox oor mao Coe-omtal] a st man mma coer) dtd sta + dq ° lomome) Qa90 mad ood Ww OD oNd aad rod cu cu cu tt emomo) Ada ate ut 09 ~new too ad a dad fomome) foeome 19 ood 9.5 10.7 1.7 1.2 1500 1800 2100 Av. nae) 10 3.0 2.9 11.6 1500 1800 2100 Av. 6.7 6 13.2 12.1 1.8 3.8 lz. 3.2 11.7 959 11.4 June June Si 4.9 3.0 0300 0900 1200 1500 1800 2100 Av. 9.9 0300 0900 dd om 1 4.0 Sal 4.6 1.8 1 “2 21.6 7.7 . 8.4 3.9 3.4 4.6 3.1 1.9 1.6 1200 1500 1800 8.0 5.9 12.8 4.2 3.0 2.7 etek bess? 9.0 “2 10.4 3.5 pie 11.5 1.0 2100 Av. 8.0 3.9 eae 8.9 4.1 11.5 3.2 July 5.0 a) 5.2 July 10.5 1.4 1.6 aL 0300 0900 1.2 0900 1200 1500 1800 2100 Av. 12 Te 2.1 1.4 on 4.2 3 3.2 4.2 4.9 4.6 6.8 yisou 5.0 3.2 12.8 13.1 3.7 3 8.2 3.2 1500 1800 2100 1200 Av. o> -o 2.4 1.9 8 5.6 4.6 9 2.6 3.2 3 5.0 12.2 12.0 2.6 1.7 4.0 5.5 4.8 2.7 arene 9.5 3.2 0 August st Au. Te 4.6 a f 4.2 4 4.6 6.6 5.0 9.7 1.4 1.0 0300 0900 1200 8.4 1.9 2 2 0300 0900 3.2 9.4 2.7 4.1 3.2 1.6 1.0 3.6 11.4 1.0 salt to 20 3.8 3.8 4.7 4.3 5.4 3.8 4.3 1500 1800 2100 Av. 10 212 11.6 1500 1800 2100 1200 Av. 3 5.6 4.1 Dee 10.7 3.7 2.4 10.8 3.7 4,2 5.4 6.2 10.0 ET. 1.0 4.1 6.0 10.0 3.0 eB he BIG DELTA. Time of BETTLES Time Ceiling in hundreds of feet Ceiling in hundreds of feet 5-9 of day 30-49 Unlin. 96-199 50-95 10-19 20-29 April 5-9 3-4 50-95 20-29 30-49 April 10-19 3-4 1-2 (6) 17.6 4.8 3.7 3.8 0.8 0.2 0300 0900 1200 16.8 6.9 0.2 0300 0900 1200 1500 1800 2100 Av. 19.7 19.6 1.4 LTA9 2.7 5.7 5.0 anak 1.2 1.21 18.7 3.1 3.0 1500 1800 2100 Av. 19.1 1.0 20 2 3.7 4.0 20.0 18.7 ene 3.1 4.7 5.7 1.3 ie) -8 19.0 3.1 nO) 18.5 May May 15.6 Oat 3.1 5.0 5.8 0300 0900 1.7 15.3 1.9 10.6 0.1 0300 0900 19.0 4.2 10 18.0 6.8 1.2 16.1 1.0 1200 15.7 eveshi 7.4 10.1 o.1 15.6 3.7 Lad 1500 1800 2100 Av. 13.8 3.2 See 3.6 5.9 Lb 9.7 9.1 1.9 15.8 1.5 <2 16.4 15.6 Av. June June 14.4 0300 0900 1200 10.3 1.8 15.8 1.2 2.3 0300 0900 15.5 5.35 4.7 1.2 1.3 Tao 1.3 ne 14.9 2.6 2.0 8.0 ae 13.8 16.0 15 2 2a. 1.1 1500 1800 2100 Av. 13.9 14.8 . 3.2 1.0 . 1.0 1.0 5.4 até 2.7 9.5 15 6.2 16c2 2.1 Av. 12.5 7.8 Gel July Let 0300 14.2 3.0 14.4 5 5.0 5.1 5.0 7 5.6 2.0) 1.8 0900 1200 13.6 12.6 2 252 7.5 8.0 9.1 3.1 4.7 BE 1.3 15.6 3.1 1500 1800 2100 15.6 Av. 1.8 1500 1800 2100 Av. L622 6.9 8.0 15.7 1.3 ce 3.0 12 1.6 16.0 9.0 ie: nienk 14.8 14.3 August August 5.2, shee 0300 0900 1200 9.1 952 8.7 1.3 1.3 1.6 0300 1.4 2.2 3.0 6 15.6 13 5.9 4 5.1 abral 1.0 1.3 2.0 1500 1800 2100 Av. 3.6 3 7.9 10.3 4.8 3.1 1.8 05 12.0 abe 1.9 1800 12.3 4.9 4,8 2.0 re) 272 10.8 2100 Av. 14.0 6.5 1.1 10.2 9.9 133 oO 0 © wf TOAD AWO onotodgrd OHM OM Od V9 OOD wo 5 imevoN ene |e Seles ore. Se anroherer ele: si amuabars | in be etre gn . SEO Soo . 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(Av. 18.0 Drei: 18.7 16.9 18.1 18.0 17.8 15.8 16.3 14.0 12.3 13.9 16.1 14.7 13.9 14.2 11.4 11.7 13.0 14.2 13.1 14.1 11.3 10.7 nlbieeey é 13.2 12.3 8.9 9.0 8.8 8.3 10,0 2.2 4.6 3.2 2.5 3.3 3.0 3.4 3.4 1.8 2.8 3.1 3.3 3.4 3.0 3.4 1.6 2.0 3.6 3.4 2.7 2.2 2.9 2.6 2.1 50-95 5.2 5.1 5.7 4.9 Geil: Tek 8.2 7.9 7.0 9.6 9.1 8.9 8.6 6.8 6.6 6.2 6.4 7.2 8.2 6.9 8.4 6.3 7.6 9.7 922: 30-49 1.6 3.2 2.4 2.0 2.0 4.8 5.0 3.4 3.0 4.2 3.9 3.8 2.9 2.9 5.8 5.2 3.1 3.1 6.3 2 5.7 5.2 5.5 20-29 April 1.0 1.0 1.0 2.2 2.6 1.8 st 2.1 3.4 3.6 2.9 2.2 2.7 2.8 May June Jul 8 3.0 ele Au 2.1 3.6 Table 31.--Height of ceiling by hour of day, and number of days per month in each height cla 10-19 Ceiling in hundreds of feet 5-9 22 1.2 1.0 A ot 2 3-4 0.1 0.1 Ae) 0.1 TANANA 1200 1500 1800 2100 Av. 0300 0900 1200 1500 1800 2100 Av. 0300 0900 1200 1500 1800 2100 Av. 0300 0900 1200 1500 1800 2100 Av. 0300 0900 1200 1500 1800 2100 Av. d]jo eyo Lek: 1.7 3.3 4 4.0 4 1.8 alt 10.0 9.2 2.4 2 1.6 2.1 ol 137 United States Weather Bureau coded data. Source: Table 32.--Type of weather by time of day, and number of deys per month in each weether cless (Ay. 1950-58) BETHEL Time Weather type Weather type Weether type i Rein Snow Hail Fog Fogw/ Smoke Thunder- of Rain Snow Hail Fog Fog w/ Smoke Thunder- of Rain Snow Szcks Thunder- day sleet smoke haze storm Gay sleet smoke _ haze storm dey slest stoke haze storm April April April 0300 pie E 2.3 0.3 0300 5.2 2.6 0300 0.2 4.6 0.8 0900 +=1.0 2.0 0.6 0900 5.3 2.2 0900 0.2 355 1.7 1200 1.6 1.7 0.6 1200 4.7 0.8 2200 0.2 3.3 1.2 1500 1.2 1.6 0.2 1500 4.1 0.9 1500 0.3 29) 0.9 1800 1.1 1.4 0.6 1800 4.3 1.0 1800 0.3 2.4 1.2 2100 1.2 1.6 0.2 2100 3.8 1.3 2100 0.3 3.0 2.0 Av. 1.2 1.8 «4 Av. 4.6 1.4 Av. a) 3.3 ial May Mey Mey 2.8 0.2 0.2 03500 257, 2.3 1.4 0300 1.4 1.4 ii 2.2 0.2 0.1 0300 3.0 2.6 0.7 0.2 03900 1.4 Dot 1.0 2.4 1200 3.7 1.3 0.1 1200 1.3 0.8 0.6 3.8 1500 4.7 0.9 0.2 1500 1.4 0.3 0.4 0.2 3.7 1800 5.0 0.6 OLIELOTS 1800 9 0.6 0.3 3.8 0.1 0.2 2100 Orit 0.6 2100 1.4 0.8 0.2 Vv 3.1 -0 sat AV. 3.6 1.4 -0 4 -0 Av. 2.5 =o -6 -0 Juns June June 4.7 0.8 e 050 4.9 0.2 aC) 0.2 03500 2.8 0.2 0.6 0.7 oO. 3.7 0.2 O.21 0S00 6.1 0.2 1.4 0.6 0900 2.4 0.4 0.4 4.3 0.1 1200 5.6 0.2 0.7 0.2 1200 3-6 0.3 0.4 0.2 3.8 0.1 0.1 1500 4.2 0.3 0.2 1500 3.2 0.2 0.4 0.3 0.2 3.7 1800 or 0.3 0.2 2800 a LEY) 0.1 0.3 3.7 0.2 2100 5.0 0.3 0.2 2100 1.8 0.2 0.4 4.0 -2 -0 -0 Av. 5.2 -0 1.0 S) Av. 2.6 -O 5 4 -0 Jul July July 0300 5.2 1.3 0.4 0300 5.9 4.4 0.2 0.3 0300 Ont 2.3 0.1 1.8 0900 4.9 abe 0.4 03900 4.8 3.3 0.3 0900 3.6 1.2 1.8 0.7 1200 44.6 0.6 0.3 1200 «5.2 a7 0.3 1200 3.9 res) 2.8 1500 Beds 0.2 0.3 0.1 1500 5.7 1.2 0.3 1500 3.21 O.4 0.21 ate) 1800 6.3 0.2 0.4 1800 5.8 HEY) 0.4 2800 AIS) 0.7 2.0 O.2 2100 Dic 0.6 0.4 2100 4.8 ig) 0.2 2100 2.8 1.0 2.0 0.2 AV Lise! -6 34 -0 AV. 5.4 2au -0 a) Av. 3.2 1.0 A) 2.9 ye) ugus% August August ae 0300 «8.2 6.7 0.2 0500 5.2 3.4 0.1 0.8 1.3 0800 «7.9 ee) 0.2 0900 5.9 2.8 0.2 0.9 ONT 1200 6.9 3.3 oO. 0.1 1200 5.7 1.6 0.6 0.2 0.3 1500 7.6 2.2 0.2 0.2 1500 3-9) 1.4 0.7 0.4 0.1 1800 6.9 2.6 O.2 0.2 1800 4.4 1.2 0.9 0.7 0.2 2100 7.6 2.6 0.2 0.2 2100 oe7 1.9 0.2 0.6 0.8 -0 -0 AV. 7.5 3.9 ul ot -0 Av. 5.5 2.0 -0 -8 -0 Weathsr type Weather types Fog Fog w/ Smoks Thunder- Snow Heil Fog Fog w/ Smoke Thunder- smoke haze storm Slest = smoke haze store April April April Ose u.2 ere 0.2 0 0.2 3 0.3 0500 0.2 pe) 0.2 0900 0.1 oot 0.3 0 0.2 a 0.2 0900 0.2 2.0 0.2 1200 0.2 1.6 0.2 1 0.3 2 1200 0.1 Onl 0.2 1500 40.2 a2 0.1 i 0.2 0) 150 0.3 1.2 0.3 1800 0.2 ise 0.1 1 0.3 1 1800 1.5 0.2 2100 0.2 1.8 0.1 2 0.4 7 2100 1.8 o.4 Av a ake oz Av == 6 Av. sa 1-8 2) Mey Mey Mey 0 0.2 ene 0.4 0.2 0300 -6 0.2 ) 7 0.6 Pet 0.6 0.2 090% 7 0.2 1200 «1.3 0.3 0.2 2.4 0.5 0.3 1200 4 0.2 1500 a9 0.3 0.2 as 0.2 0.2 150) 2) 0.2 1800 2.0 0.2 0.1 0.1 2.2 0.2 O32 O2F 1800 ie) 0.2 2100 ek 0 0.2 2.9 0.3 0.2 0.2 2100 2 0.2 Av. Lz aeE -0 2.0 -3 -0 ae 0 Av. 1S oa) June June June 0300 3.6 0.2 03500 PY fi 0.35 0.4 0300 aT, 0.7 ogs00 2.4 0.1 0.35 0900 2.6 0.2 0.35 0900 2.0 0.8 1200 2.8 0.2 0.2 1200 «2.3 0.1 0.2 0.3 1200 1.7 0.7 1500 3.0 0.2 0.2 0.3 1500 2.9 0.2 0.2 1500 1.6 0.8 1800 3.6 bee g 0.2 0.6 1800 3.7 0.1 0.4 0.2 1800 2.9 0.6 2100 2.1 0.2 0.2 2100 3.1 0.1 0.3 @.2 2100 °1.9 0.6 Av. aE) 2 ae ea Av. 229) Su .4 oe Av. 1.8 EY, July July July 0300 4.2 0.7 0.1 0.9 0300 4.6 0.3 0.3 2 2.0 0.2 at 0900 4.1 0.3 0.6 0900 4.3 0.2 0.2 1 3.0 2.9 1200 2.9 OL. 0.6 2200 3.7 0.1 1 0.2 2.3 0.2 2.6 1500 3.9 0.1 0.7 1500 3.8 0.3 1 0.6 2.9 eal 2.9 1800 3.5 0.2 xtexh 0.35 1800 ee 0.1 zl 0.2 3.3 2.4 220 3.9 0.2 ph 0.4 2100 0.2 i 2.8 2.2 Av 3.7 -3 0 -5 oat Av. 2 El z Sel 2.7 -0 -0 2.4 August August? August 0300 4.0 0.6 0.2 4.9 2.8 0.2 0.8 0300 2.4 0.3 2.6 0900 4.0 0.2 0.4 3.6 1.3 OSL aa 0300 3.2 0.2 2.5 1200 2.6 0.2 3.5 0.6 1.4 31200 2.8 1.4 1500 3.2 0.2 0.4 3.7 0.3 0.8 1500 3.1 0.2 1.3 1800 «3.1 0.2 0.2 4.2 0.2 0.9 1800 3.9 0.1 0.3 2100 = 0.8 4.1 0.2 0.6 2200 5.8 1.2 Av. -5 -0 1 -4 -0 4.0 =9 2 2.0 Av. 3.2 a 1.4 138 Table 32.--Type of weather by time of day, and number of days per month in each weather class--Continued (Av. 1950-58) GALENA Time Weather type of Rain Snow Hail Fog Fog w/ Smoke Thunder- day sleet smoke haze storm GULKANA Time Weather type of Rain Snow Hail Fog Fog w/ Smoke Thunder- day sleet smoke haze storm HOMER Time Weather type of Rain Snow Hail Fog Fog w/ Smoke Thunder- day sleet smoke haze storm April April April 0300 0.4 4.1 (eat 0300 1.3 0.2 0300 2.4 2.2 1.0 0900 «(0.6 3.3 0.7 0900 1.2 0900 2.6 aaa 0.9 1200 0.4 239) 0.2 1200 0.1 aead 1200 2.9 1.8 0.3 1500 0.6 2.4 0.21 1500 0.4 1.0 1500 3.3 2.3 0.4 1800 OST. teil 0.2 1800 0.3 0.8 1800 2.6 1.9 0.6 2100 0.8 Sg. 0.3 2100 0.4 0.9 2100 2.6 1.8 1.0 Av. -6 Hh ates Av. 72 1.0 0 Av. 2.7 2.0 ole May May May 0300 1.7 0.8 0.2 0300 «61.2 0.3 0.3 0300 3.2 0.7 0900 «2.3 0.8 O/T 0900 «(1.0 0.2 0.3 0900 2.8 0.2 1200 2.2 0.3 1200 1.1 0.2 0.2 1200 2.8 0.2 0.1 1500 2.8 0.3 1500 nbs) 0.3 O.1 1500 4.6 0.1 1800 2.6 0.6 1800 1.8 0.1 1800 3.3 Oo 2100 (1.6 0.6 2100 0.9 0.2 O52: 2100 3.1 Of2 Av. 2r2 -6 .0 Av. 1.3 ue eo .0 Av 3.3 (0) A June June June 0300 «3.1 130 0.21 0300 2.0 0.6 0300 3.6 12 0900 2.2 0.2 1.3 0900 «2.2 0.1 0900 «(3.1 0.3 1200 3.0 1.0 0.1 1200 1.9 0.3 1200 2.9 0.3 1500 2a 0.1 1.0 1500 2.6 0.3 1500 3.9 1800 2.6 Os1- 051 1.3 0.1 1800 2.9 0.4 1800 2.6 0.2 2100 1.8 1.0 0.21 2100 (1.9 Oval! 2100 3.4 0.4 Av. 2.5 .0 oak 121 ok Av. 2c2 ene 72 Av. 3.3 iA July July July 0300 3.9 0.9 nL 0300 4.4 0.1 0.8 On 0.2 0300 4.4 A) 0.2 0.21 0900 «3.4 0.8 0.2 a) 0900 =3.6 0.4 0.1 0900 2.9 0.4 0.2 1200 3.2 0.2 0.2 abey) 0.1 1200 2.8 0.1 0.2 0.1 1200 3.4 0.1 0.1 1500 3.2 0.6 On1 1.8 0.1 1500 3.0 0.2 0.3 0.4 1500 3.6 0.4 0.1 1800 4.9 0.2 Blea: 0.2 1800 63.2 0.3 0.7 1800 3.7 0.4 Ofn 2100 3.2 0.4 art) 0.1 2100 3.8 0.2 0.3 0.1 2100 3.4 0.7 0.1 Av. 3.6 5 el 228 pae Av. 3.5 Ae) 23 -0 2 12 Av 3.6 -6 Ae) =a August August August 0300 «6.5 1.2 0.21 0300 4.1 0.1 12 0300 «3.6 2.3 0900 6.4 1.0 0.5 0900 «3.8 0.4 0900 4.3 0.8 0.1 1200 5.9 0.5 0.4 1200 «44.2 0.21 1200 5.4 0.6 1500 6.1 0.2 0.4 1500 4.7 On 1500 5.0 Ole 1800 6.0 0.2 0.2 0.1 1800 4.4 1800 4.8 0.7 2100 5.2 0.4 0.2 2100 4.8 0.2 2100 5.4 252: Av. 6.0 76 73 fe) Av. 4.3 +0 BS Av 4.8 1.0 ie) ILTAMNA KOTZEBUE LAKE MINCHUMINA Time Weather type Time Weather type Time Weather type of Rain Snow Hail Fog Fog w/ Smoke Thunder- of Rain Snow Hail Fog Fog w/ Smoke Thunder- of Rain Snow Hail Fog Fog w/ Smoke Thunder- day sleet smoke haze storm day sleet smoke haze stora day sleet smoke haze storm April April April 03u0 ae2 4.3 0.8 0300 0.8 5.8 2.3 0300 0.1 2.3 0.4 0900 1.0 3.6 Tt 0900 «(0.3 4.7 anti 0.2 0900 «60.3 Die 1200 1.4 3.0 Ont 1200 0.3 5.1 2.3 0.2 1200 0.3 age) 0.1 1500 0.9 2.8 abso) 1500 0.6 4.9 2.1 0.1 1500 0.4 abi 1800 ibe) 3.2 alee) 1800 0.8 4.8 ort 0.1 1800 (Oey ais lojmal 2100 1.1 3.4 1.6 2100 (0.8 5.2 a) 0.21 2100 0.1 1.6 0.2 Av. att 3.4 ikea Av. -6 5.1 252) Ea) Av. Be 9 22 0300 4.6 0.8 1.3 0300 «#41.9 ea 2n9 0300 «1.6 0.8 0.8 0900 2.8 0.7 0.7 0900 «(21.9 ryat 2:8 0900 «(1.2 0.4 0.3 1200 etl 0.4 0.3 1200 1.8 1.0 abe) 1200 ples 0.3 Oral 0.1 1500 3.6 0.3 0.3 1500 1.3 O29, 0.9 1500 2.0 0.4 0.3 1800 3.3 0.3 0.2 1800 1.2 0.8 aloe 1800 «(1.3 0.4 Ona 2100 4.7 0.2 0.7 2100 2.0 1.1 Lint 2100 _=i1.7 0.8 oat Av. 3.6 75 “6 Av a7 1.4 ale) Av. 1.5 “5 +3 Ae) June June June 0300 4.0 1.6 O.1 0300 3.2 29: 0300 4.0 0.2 0.6 o900- 3.8 alaal 0900 2.0 0.1 2.6 0900 «3.4 0.6 1200 3.7 0.4 1200 «2.3 2.3 1200 2.3 0.3 1500 3.9 0.1 0.1 1500 1.3 or) 1500 2.4 0.4 0.2 1800 2.9 OR: 1800 1.6 alee) 1800 3.2 0.2 0.4 2100 3.3 0.3 0.1 2100 3.0 2.4 2100 2.1 0.4 0.1 Av. 3.6 .6 (e) (e) Av. 252 .0 2.3 Av. 2,9 .0 4 al July July July 0300 3.0 4.6 0.3 0300 4.1 2.8 0.4 0300 4.4 ateul 1.4 0900 3.8 259 0.2 0.3 0900 2:9 272 0.4 0900 2.9 0.1 1.8 1200 3.9 OF9 Ora: 0.4 1200 2.8 1.4 0.3 1200 4.1 1.2 Oe 1500 4.0 aby (oes 0.6 1500 3.7 0.9 0.3 1500 4.2 Ong 0.3 1800 4.6 0.8 0.3 Oed 1800 3.8 1.0 0.4 0.1 1800 3.4 0.1 0.9 O.1 2100 4.0 0.9. 0.3 2100 3.4 1.3 0.4 0.1 2100 4.3 0.9 0.3 Av 3.9 a9: 1 3 (0) Av 3.4 6 4 .0 Av 3.9 2) el ol August August August 0300 6.6 4.3 0.1: 0300 7.0 2.3 0.1 On 0.1 0300 5.0 0.9 0.3 Ove 0900 «45.8 eaeA/ 0900 =5.3 2.2 (oat 0900 «4.7 0.3 0.2 1200 5.8 1.6 Of: 1200 6.3 ples) Ore) 1200 4.3 0.4 0.2 0.21 1500 5.6 2.0 1500 5.9 1.2 0.2 1500 3.4 0.2 0.2 1800 5.9 2.2 1800 bt) 1.4 0.2 1800 5.1 O.1 0.2 2100 _ (‘5.8 Cath 0.1 2100 5.3 1S 0.21 Oe: 2100 +5.2 0.2 Av. 5.9 2.6 0 Av 5.8 ay? a) S me) Av 4.6 73 22 ee 139 vel (Oem lO AO oO Cy sto rast ° re ret oe oO aoe u elie ma mn 101 st De] wo m re aM Vot}et ’ Ciera par “ ‘ ie He at ate ate fi (- aaq0e o i) °o OoOo000 An sh rim 10 eth efo too oo aol’ e ec ii UI in w 1] 00 rt i} LS a ela aet fw ela ra] MO rth wolo 19 oO an wa elite) tae . ‘ ' : abet shee : ‘ ‘oy ‘ : a ish ot boo Nilis ao hielo a aoo0aa oo ra) Aertel at a ilo loo w te is 4 5 rt el rh " ' a) a oO f tr " ’ ‘ a i YO 0 & o bh Oe vl °o rio in Ded fter ' oy ' : Hg 8 Bi AM Met et et c fe) ° oO Flot | au “ \ f ea UO Pala om (s) 0 rh ef O19 wl a { we Shee helene ceed Wed Liner eer ene ba re tet a (-W-Vf-K-] aaa a ravmratl (ied rh bh bc 0 belt sal! da he i a ain i=) Qo [a a 1 ia Ol] + oO ne el ia a} te) cil fia) wy Ble or oo allay O, 8 7 e a ' nt «i oO 0 bl be cox Baie - a oa °o a a ty f 4 0 ‘ ria S) 0010 Hl d eo rl ao000 by ae i " rl S) el rt jo rit a | ol °o oO ia) 2°a ‘ ir) 10 % ‘ o] a 19 ” 9 el elettet nia MQ O]et a i) aa ao oo oo alr (=) p ) em ae Pel pr eeet pate et a se Fe siesenns see ote . . mt tee $ : ce 4 eirheerrecare cae ren975, SPhebs : <0 : y sacked AREER Se 2" oe SSNS Ard Cece ret | ; Mew ke specie 22-408 © ck prs et “e Se SE ecm 3 Mies bly tae * -s te bier in 2 m ay tart + Sate WE SEARS SRE WR ST “i ‘ q ; :