SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 152, NUMBER 5
(PusLicaTtion 4711)

Roebling Fund

SUPPLEMENT TO
AekLINGIRANGE FORECAST ‘OF
PRED states PRECIPITATION
(SMITHSONIAN PUBLICATION 4390)

By
CeGeABBORDESe
RESEARCH ASSOCIATE, SMITHSONIAN INSTITUTION
AND
MRS. LENA HILL
RESEARCH ASSISTANT

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION PRESS
MAY 31, 1967

LIBRARY

AS:

OF
! NATURAL HISTORY

PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.

Roebling Fund

SUPPLEMENT ©
A LONG-RANGE PORECAS?T OF
UNITED STATES PRECIPFIDATION
(SMITHSONIAN PUBLICATION 4390)

By CG. ab BO Disc

Research Associate, Smithsonian Institution
and
Mrs. LENA HILL

Research Assistant

In 1957, AssIsTED By Jonathan Wexler, electronic computer, Mrs.
Lena Hill, Mrs. Isobel Windom, and Miss M. A. Neill, I completed
computing and preparing for publication forecasts from 1950 through
1967 of monthly and 4-monthly percentages of normal precipitation
for 32 United States cities. This study was issued by the Smithsonian
Institution in January 1960 as Publication 4390, entitled A Long-
Range Forecast of United States Precipitation.’ Besides the customary
free distribution of nearly 1500 copies to libraries and selected indi-
viduals, the Smithsonian sold over 5000 copies to institutions and
individuals desiring information on probable future precipitation.
Occasionally orders for Publication 4390 are still being received. I
suppose, therefore, that a continuation of its forecast of monthly
precipitation through 1970 will be acceptable to many.

In 1961 the Smithsonian issued Publication 4471, A Long-Range
Temperature Forecast,” forecasting monthly temperatures for 10 cities
through 1967. The first pages concerned Publication 4390 and found
that precipitation was forecasted as well in 1959 and 1960 as it had
been in the years 1950 through 1958. It also found that the agreement
of prediction with observation was as good for intervals of wide

1 Smithsonian Miscellaneous Collections, vol. 139, No. 9, 1960.
2 Smithsonian Miscellaneous Collections, vol. 143, No. 5, 1961.

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 152, NO. 5

4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 152

departures from the normal as when observation averaged within
25 percent of normal.

Readers of this present publication are referred particularly to
Smithsonian Publication 4390, for a detailed description of the method
of making long-range forecasts. The following Table 1 gives forecasts
of precipitation from 1967 through 1970, tabulated percentages of
monthly departures from normals at 32 cities of the United States
as listed in Table 9 of A Long-Range Forecast of United States
Precipitation (Smithsonian Publication 4390).

TABLE 1.—ForEcAST PRECIPITATION 1967-1970. PERCENTAGE OF DEPARTURES FROM
NorMALs As GIVEN IN TABLE 9 oF SMITHSONIAN PusLicaTion 4390,
A Lonc-RANGE Forecast or UniIteD STATES PRECIPITATION.

Abilene, Albany, Albany, Augusta, Bismarck, Charleston, Cincinnati, Denver,
ex. ING Oreg. Ga. N.D. Se hio Colo.

1967
Tava, 4.24 3 =; 4 = =i6 = 4.26
Feb. +39 —23 —26 —30 —14 —/ —29 SEG
Mar. +30 —8 —33 +1 —26 0 —13 —12
Apr. +5 +33 —37 —22 —17 +18 —6 —18
May +32 +23 165 —37 —4 aL35 +3 aU//
Tane +464 mi 33 ms 5 +44 44 46
uly +19 177) 29 ip +50 4.63 == nuae
Aug. —15 +1 —26 —5 +27 —8 —10 +30
Sept. —29 16 255 +16 +10 +418 ney: 4.24
Oct. —23 —2 —13 —6 —12 +8 +20 +8
Nov. SL 27) —l —31 —19 +5 0 +24 2)
Dec. +22 = 12 —30 —21 +1 —9 —l1 12
1968
Jan. jal iy 6 a3) wi 95 =I 25
Feb. —45 +39 —17 —28 +9 —6 = —30
Nie ee 4.29 44 4.5 44 +16 48 0
Apr. +36 +23 0 —6 —25 +29 —8l —6
May Wj 8 =e 6 “ip 4.47 —45 ay
June +50 —28 —39 —21 +5 +76 —12 17
ete 414 —18 —44 +19 4 4.66 +50 a5
Ane coi , ZAG +50 +419 435 sez 4.28
Sept. 5 8 4.28 +61 +50 a7 +67 46
Oct. +15 —21 +10 +42 +40 —10 +66 +54
Nov. +18 —27 +16 © +13 +13 —43 +35 +56
Dec. +5 —27 +18 —8 —15 —27 +9 +57
1969
Jan. —27 —10 +24 —16 —27 0 —13 +28
Feb. —20 +21 —2 —29 —= 25 0 —19 —/
Mar. —9 +50 +32 —30 —32 —5 —18 —24
Nave, ny 4.25 414 —30 414 4116 i —39
May —12 +38 —30 —10 +36 +16 +10 —43
June —=55) +38 —=2 +20 +44 +16 SL 3S) —18
Tis 5% +10 = 4.20 +40 0 4.38 “7
ee 27 6) 4.24 195 ne +419 435 ay
Sepee 10 —44 4.26 +10 = ney, 49 if
Oct. 4.29 —49 4.28 6 4.28 0 35 soi
Mens 4.38 —40 +419 4.28 17 | H5) 414
Wee +419 ASG 47 +20 +6 10 —45 499
1970
Jan. —9 +36 —2 +3 —50 —25 +44 +16
Feb. —l1 +47 0 —3 —§ —36 —22 —6
Mar. +10 +36 +7 +20 —14 3) —l1 —29
Apr. —9 +13 +10 +18 —19 —3/ —22 —7
May 0 +9 = 52 +35 —12 —2 —18 +6
June —9 +4 55 +39 —22 +43 —6 S15,
July +24 —31 +49 +21 +14 +40 —6 +36
Aug. —10 3) 1h; 4.20 197 421 0 4.40
Sept. —10 —28 +78 —4 +4 —=i7/ +7 +59
Oct. +30 2g), 4.55 +6 By 15 2a 4.39
Nov. +43 —26 22 +1 —5 —35 +1 +23

Dec. +49 —40 +2 —7 +11 —52 —12 —/7

6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 152

TABLE 1—ForecAST PReEcIPITATION 1967-1970.—Continued.

Detroit, Eastport, El Paso, Helena, Independence, Eirtle habia Madison, Monta
; ae

Mich. Maine Tex. Mont. Kans. r Wis.

1967

Jan. +6 —51 —73 +3 +6 —13 +14 —|
Feb. —6 —31 —/5 —4 +48 —15 +28 aS
Mar. —19 —19 —— oy +9 +39 —26 +12 +4
Apr. —46 —4 —22 shy) +32 —38 +20 —28
May —61 +9 +64 +43 +33 —33 +10 16
June —26 +3 +87 +5 = 17 2 +15 —d4
July —54 —6 +44 —/ +37 —25 +1 +10
Aug. il = +62 +9 —4 ——24 +15 +]
Sept. —38 —21 +39 +36 +3 +3 +15 +54
Oct: —14 —27 aL7) +32 +28 227) —6 +66
Nov. =Ej15) —28 +56 +10 +10 +24 —10 +40
Dec. +59 —31 —7 +36 +7 +19 3 +29
1968

Jan. +1 —36 —30) +43 +25 +41 —1 —4]
Feb. +19 — fl) —/// —14 +39 +15 +4 4
Mar. +18 —— —58 +14 +14 +20 +8 —36
Apr. =f +14 —3/ —39 —l +30 +] —36
May +14 +21 +16 —55 +8 +23 +39 +3
June +13 +49 +33 —94 +42 25 +1] a,
July S227) +44 43 —52 +17 +22 ==5) +429
Aug. +26 +29 18 —55 +49 JEH)) 15 +22
Sept. +19 +26 +29 —( +9 +36 —13 SEZ
Oct. se 1/1 +42 +40 +36 +7 +66 —o +32
Nov. ie ==35 sey +40 +22 4E55 —30 —2
Dec. —29 +24 +40 +3 12 +34 —58 —23
1969

Jan. —10 —4 —10 —12 —26 +7 —55 —37
Feb. —27 14 ——I() 7 —48 +11 —33 —36
Mar. —15 —9 +6 —62 —58 —18 0 —26
Apr. ay =e +49 —4A7 —26 —2 +14 —7
May —44 —37 +26 —Jo —23 = +10 424
June —53 —33 31 —A\) —6 2 +18 +32
July 12 —39 +144 —17 —4 —12 S25 +23
Aug. +20 —15 +15 —25 —23 —17 12 434
Sept. +38 +4 oe, +2 +7 —20 +14 +63
Oct. +30 SE 11) —3 sky 4 —23 +22 4-45
Nov. SES —15 +26 3 —8 —/ +19 +20
Dec. +6 =f +10 —9 +18 12 +23 —31
1970

ane tke —10 +13 +1 +8 —14 +23 —48
Feb. —14 —3 +37 +13 +28 —16 +13 —58
Mar. =I ==) +43 +1 +3 —51 +12 i
Apr. —35 —21 +53 42 —4 —70 +17 —18
May —10 —47 +30 +14 —8 —78 = —45
June = 4 —46 +10 +13 +4 —51 —5 —4
July +26 —39 oy +27 +28 —— Jf, —3 —16
Aug. 427 —22 —55 +53 +8 —37 +38 +29
Sept. +11 —1 —42 +42 —18 —I3 +14 +65
Oct. +7 +24 —39 15 —22 +4 +3 +53
Nov. —10 +29 —6 —34 —34 2115 —19 +38

Dec. —24 ail —45 =a 22 ih —27 ae

NO. 5 FORECAST OF U. S. PRECIPITATION—ABBOT 7

TABLE 1.—ForecAst PRrEcIPITATION 1967-1970.—Continued.

Nashville, Natural Bridge, Omaha, Peoria, Port Gibson, Rochester, Sacramento, Salisbury,
Tenn. Ariz. Nebr. Til. Miss. INN Calif. NG:

1967
Jan. ay 278 +18 +49 +418 =H 4.93 =
Feb. +9 —23 +13 +41 -E5 —10 +94 +16
Mar. —20 —22 +2 +12 +11 —37 +68 +18
Apr. —8 +2 —5 +13 —27 —34 +68 +9
May —24 +24 0 —10 —13 —36 Sel +33
June yy, 4 44 35 ei) —41 —15 +40
July —38 ng 4.42 —50 =e es ip 4.25
Aug. 75) 4.49 424 id =A tay =i +24
Sept. 16 hte 4.34 4% =F +66 36 HED
Oct. 4.25 31533 4092 48 ik; 458 247 438
Nov. 4.49 4.45 ainag Bey, =iG 431 —66 4.30
Dec. aag7 +30 asi) a5 a7 =) —64 4.28
1968
Jan. Ig 422 ~6 4.26 113 4 i I;
Feb. —8 —4 +30 +32 +12 +1 +48 —10
Mar. —36 +2 —19 +21 —19 +27 +82 —28
Apr. a4 +9 sy +50 2a 411 suze =
May —16 —17 —$8 +26 +11 +28 +56 —27
June —8 —29 —20 +23 +26 —2 +24 =115
July 150 47 7 9 +8 a ==44 ES
Aug. +28 +60 —3 +2 +10 —9 —60) +20
Sept. +37 +49 +38 —31 —l1 —30 —47 +29
Oct. +21 —33 —15 —52 +9 —10 —67 +16
Nov. 4.35 =p ioe ay 12 =7) 256 196
Dec. +38 —50 2 8 +2 —12 —16 aE
1969
Jan. +37 —62 +12 +9 +4 —4l1 --29 —39
Feb. +23 —24 +6 +17 +22 —26 +63 —37
Mar. —10 +3 +83 +23 +20 —16 +85 —34
Apr. —39 —26 +73 +10 +36 +13 +87 —33
May —21 —4 +35 +11 +15 +12 SE 3i7/ —36
June —24 —53 —49 +11 —10 +33 —29 —40
July —14 4] —33 —15 =f 35 —57 —5
Aug. +8 3p 57 —46 8 412 _5i 2
Sept. —15 +71 —13 —2 +35 +26 —§ —15
Oct. 271) Segy) = 35 Tif Susp 1p, =o 270
Nov. ae) iy —28 Le 458 +20 —49 a284
Dec. =14 2770 =6 am: 434 ii —44 35
1970
Jan. —14 —13 +37 +12 —23 +13 —20 —25
Feb. —7 —10 +33 +3 —10 —l +50 —24
Mar. —35 +25 —4 +1 —27 —l1 +36 —l1
Apr. ay 237 =] =i +15 =f 452 5
May —17 —31 —48 —33 —5 —6 +31 —2]
June —1 —2 —65 —38 —36 —15 —4 +11
July —2 +29 —43 —51 —41 —13 —91 +38
Aug. +7 +59 —32 —68 —44 —17 —98 +75
Sept. 0) +57 —1 —60 —14 +12 —86 +87
Oct. +11 +83 —7] —28 +21 —l —30 +47
Novy. +23 +12 —34 +2 +14 +3 —32 +8

Dec. +20 =33 —16 +26 +3 —14 2 +4

8 SMITHSONIAN MISCELLANEOUS COLLECTIONS iia

TasLE 1.—ForecAST PRECIPITATION 1967-1970.—Continueu.

Salt Lake City, San Bernardino, Santa Fe, Spokane, St. Louis, St. Paul, Thomasville, Washington,
C vi i DG

Utah Calif. N. Mex. Wash. Mo. Minn. Ga.

1967

Jan. +19 55) —42 —7 —26 —5 —10 —16
Feb. —4 —14 —47 —9 ——9/) =e aE) a5
Mar. en =i\2 S51! +12 —A() —l1 +13 —44
Apr. —65 —3 +12 +2 —S8 —18 +12 —18
May —62 oes ee ee 4.25
June 5/5 +8 7 +15 +30 +2 +22 435
July 14 —8 —7)| +20 +61 = 23 +23 +33
Aug. ==) +2 —39 +6 +66 +16 —27, +23
Sept. +20 +43 +42 +9 +76 —3 —28 SEily/
Oct. SEIS +43 St5y/ +17 +35 +13 —24 —/
Nov. +40 +24 +48 +64 +17 —25 —28 +15
Dec. +18 0 —13 +60 —19 —39 —12 —1
1968

Jan. +2 —3 a +13 —7 =! +8 —36
Feb. —23 —28 —24 2 —29 —20 +26 —46
Mar. ==)! —39 —45 —18 —14 —13 +34 —49
Apr. —33 —38 —40) —13 —9 +11 +67 —26
May —48 +34 —32 —30 —25 +9 +66 +24
June —13 +29 —2 Su! —29 +12 +36 +34
July +6 +20 279 24 —15 +18 +4 +25
Aug. +20 —2 +54 +16 +28 +9 +10 +18
Sept. +38 0 +63 +22 +21 —16 —5 +18
Oct. +49 +43 +80 +24 +10 —9 —3 SES)
Nov. 57 +38 +46 +20 —20 +11 —23 —21
Dec. +24 —52 +10 +11 +15 122 —19 —9
1969

Jan. —3 —6l —24 +8 29 +42 +8 —25
Feb. —42 —57 —15 —22 +16 +49 sE5E —24
Mar. —63 —23 —46 —4] —19 +33 +41 —9
Apr. —63 —27 —16 —25 —5] +17 +32 +18
May —64 —1 + —50 —49 —13 +13 +16
June —30 +27 +36 —43 —26 —22 —39 +35
July —21 +44 -L50 —8 +14 +10 —73 +24
Aug. +32 +31 1-13 ——2, +32 +12 —60 —l1
Sept. +36 +17 —l4 —§ +53 +4 —30 —6
Oct. +57 +24 ——p —29 +45 —34 —|1 —3
Nov. +69 —10 +9 —8 +57 —3l1 —18 +15
Dec. +32 —39 +37 +55 +52 +3 —30 —l1
1970

Jan. +3 —44 +21 +49 +23 +10 —44 —33
Feb. +2 —12 —12 —14 —6 +10 —11 —37
Mar. +2 —4 15 —12 —43 +19 +4] —84
Apr. +] —27 7 —26 —40 +20 +48 —83
May +7 —29 +15 —6h —40 +4 66 —48
June +16 —39 +28 +25 —8s +9 +74 +1
July +7 +16 —4 +47 +35 0 +63 +48
Aug. +18 +30 —5l +57 +19 —8 +37 +34
Sept. —12 4. —5l +50 —13 —4 +18 +24
Oct. —22 —16 —24 +37 —34 0 +11 +10
Nov. 0 —]] —58 +47 —26 —1 13 —32

Dec. +7 +8 —18 +68 —46 —12 +23 —49