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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
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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
=
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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
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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
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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 {
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Figure 57
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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
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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
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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
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STUDIES WERE MADE
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Figure 60
ea g -eameaige yi
ay,
nana A i. i
featge: Gerrneee | Lp e we OR
athe
S| isi ae ee
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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.
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25-34.
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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.
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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