« PrejšnjaNaprej »
At the beginning of the year 1901 the weather bureau office at San Francisco made an effort to collect reports concerning the amount of snowfall in the mountains chiefly for the purpose of affording some data upon which forecasts of the probable supply of water available for irrigating, mining, and other purposes might be based. Not for many years had the snowfall been so heavy in central and southern California as during the winter of 1900-1901 and the outlook for an abundant supply of water so promising. It does not necessarily follow that a winter of heavy snowfall is succeeded by a season of bountiful water supply. In some States it has been found that dry ground absorbs so large a proportion of snowfall under certain favorable conditions that the anticipated run-off is not reached. Again, the melting of the snow may not occur rapidly enough and the evaporation prove excessive, especially if high north winds or mountain winds of the "Chinook" type prevail. Finally the manner in which the snow packs as it falls will determine largely the rate of flow during the ensuing warm months. During the month of February, 1901, the snowfall generally in the mountains of California was heavy. Particularly in the southern half of the Sierra Nevada and Sierra Madre was this the case. The following forecast was made at the close of February and was amply verified:
There is every prospect of an abundant supply of water during the coming spring and summer months. In the mountains of the central and southern portions of the State there is stored a sufficient quantity of well-packed snow, probably in excess of the amounts for any season for four or five years past. In northern California, while there will be an ample supply of water, the snowfall has not been as heavy as might have been expected during the wet winter.
Following are the notes made by different observers who were kind enough to make snowfall reports:
Bear Valley (near Emigrant Gap).-Snowfall heavier than last weather has been too warm for snow, but have had plenty of rain. 14 feet on a level, but since then it has not been more than 4 feet. Bodie.-Snowfall last season, to January 26, 42 inches; this season, to same date, 139 inches. (Benjamin
year, but considerably less than average. The Until four years ago the snowfall was from 8 to (James Rose.)
Edmanton (Meadow Valley).—Average snowfall, 70 inches; this season, to January 26, 136 inches; last season, to same date, 47 inches; total precipitation this season, same date, 50.34 inches; last season, 51.35 inches. (J. A. Edman.)
Greenville.-Average snowfall, about 36 inches; this season, to January 3, 43 inches. The snow is melting slowly and will be of much benefit to crops. (C. H. Higbie.)
Iowa Hill.-The snowfall in 1890 was about 100 inches. It has been decreasing every season; last season, 8 inches. (C. F. Macy.)
Laporte.-Snowfall last January, 98 inches; this year, to January 26, 94.5 inches. The average snowfall from July 1 to June 31, for five seasons, is 288 inches. The average January snowfall is 76 inches. (C. W. Hendel.)
North Bloomfield.-The supply of water is probably not greater than last season, but depends upon February and March storms. Average snowfall, about 24 inches; above timber line, 84 inches. (L. L. Myers.)
North San Juan.-Average snowfall, 2 to 3 inches; at timber line, 6 to 8 feet; above timber line, 10 to 14 feet. (Dr. A. Fouch.)
Quincy.-Average snowfall, about 42 inches; will have best water season since 1897. (W. J. Edwards.)
Redding.-Average snowfall, about 7 inches. In mountains to the west, snow very heavy and much above average; to the east (Sierras), much lighter. (L. F. Bassett.)
Rosewood.-Average snowfall, about 8 inches; for 1899, 22 inches; 1900, none. (C. F. Stivers.) Shasta.-Average snowfall, 8 inches; this year above average. (Dr. T. J. Edgecomb.) Sisson.-From appearance of surrounding mountains there is double the amount of snow to same date last year. Mount Eddy and Mount Shasta are covered and canyons are full. (C. F. Galbreath.)
Susanville.-Snowfall to January 31, 1894, 23 inches; 1895, 117 inches; 1896, 16 inches; 1897, 36 inches; 1898, 9 inches; 1899, 50 inches; 1900, 45 inches. (James Branham.)
Truckee.-Average snowfall, 95 inches; at timber line, 13 feet; above timber line, 16 feet. Snowfall for this season above average. (C. B. White.)
Yreka:-The snowfall this season, 63 inches, is greater than in any year since 1890 and the heaviest for one storm ever known. (Robert Rankin.)
COAST AND BAY SECTIONS.
Eureka.―In the mountains, at an altitude of 4,000 feet, the snow is deep. It is reported that the snowfall is unusually heavy in Trinity and Siskiyou counties. (A. H. Bell.)
Iaqua, Humboldt County.-Average snowfall; about 18 inches; this season above average. More precipitation this year than in any year since 1862. (W. E. Williams.)
Simmler, San Luis Obispo County.-No snow to date; average fall about 4 inches. Rainfall to January 26, 10 inches; total last season, 5.70 inches. (A. F. Hubbard.)
SAN JOAQUIN VALLEY.
Bigtrees, Calaveras County (elevation 4,700 feet).-Snowfall, November 19 to January 10, 50 inches; rainfall to January 11, 29 inches. (J. M. Hutchings.)
Bishop.—Snowfall more than for several years; rainfall in Owens Valley greater than usual. (W. A. Chalfant.) Fort Tejon, Kern County.-Snowfall not above average, which is about 3 feet, and from 4 to 5 feet above timber line. (J. G. Stitt.)
Independence.-Snowfall at station, 7 inches-about double that of last year and more than average for past four years. The water supply will be very much greater than last season. (John J. McLean.)
Summerdale. This season's snowfall (to January 31) is about 12 inches more than last season's, but less than average. The average at timber line is 3 to 4 feet and above timber line 10 to 15 feet. The rainfall has been the heaviest on record. (J. H. Lowry.)
Tehachapi.-Snowfall exceeds that of last season.
Average, about 3 feet; in the higher mountains, 12 feet.
(W. H. Knapp.)
Tejon Rancho, Kern County.-Creeks and springs are lower than I have known them for twenty years past. (R. M. Pogson.)
Thebe, Inyo County.—Snowfall greater than last season's. Average, about 12 inches; at timber line, probably 8 to 10 feet. (C. Kispert.)
West Point.-Snowfall about the same as last season's and considerably less than average. (T. A. Wilson.)
Beaumont.-Snowfall greater than last season's, but less than average; at timber line the average is 15 feet. (J. W. Elder.)
Campo, San Diego County.-Snowfall exceeds last season's, but is less than average; the same is true of rainfall. (A. Campbell.)
Cuyamaca.-Average snowfall for thirteen years, 33 inches; this season (to January 26), 1 inch. Owing to heavy rains, the water supply will probably be greater than last season. (G. H. Nelson.)
North Ontario.-Average snowfall in the mountains, 8 to 12 feet; the fall exceeds last season's, and the water supply will be greater. (A. P. Harwood.)
San Jacinto.-Snowfall in the upper valley on the 27th and 28th of January, from 6 to 10 inches. (C. A. Harper.)
Bear Valley (near Emigrant Gap).-This season's snowfall is about 75 inches greater than last season's. Snow on ground February 9, over 5 feet; February 25, 30 inches; at the summit February 10, 14 feet. Heavy warm rain reduced snow. (James Rose.)
Blue Canyon.-Very little snow left here now (February 23). The snowfall has been 4 feet greater than last season's. (J. Knapp.)
Bodie.-Snowfall greatly exceeds last season's; 48 inches on ground February 20.
Bowman's dam.-Snowfall much greater than last season's; 54 inches on ground February 28; 8 feet February 10, which was reduced by warm rains. (A. F. Hippert.)
Castle Crag.-Snow on ground February 28, 10 inches; snowfall greatly exceeds last season's. The water supply will be much greater than last season. (H. O. Wickes.)
Cedarville.-Snowfall to February 25 has been 29 inches in excess of last season's; now on ground, about 12 inches. (T. H. Johnstone.)
Dunsmuir.-Snowfall greatly exceeds that of last season; on ground February 6, 60 inches. (R. K. Mont
El Dorado.-Snow on ground February 23, 4 inches; average fall at timber line, 12 feet; above timber line, 16 feet; snowfall greatly exceeds last season's. (C. E. Deuden.)
Elder (Humboldt County).-Snowfall greater than last season's; on ground February 25, 6 inches. (William Lyons.)
Eureka.-On South Fork Mountains, 100 miles east, snow is reported 20 feet deep. Warm rains are melting snow rapidly. (A. H. Bell.)
Georgetown.-Snowfall exceeds last season's; 27 inches fell during February, but there is none on the ground now. (C. M. Fitzgerald.)
Grass Valley.-Snowfall exceeds last season's; none on ground at present. (B. F. Berriman.)
Greenville.-Eight inches of snow on ground March 1, and much heavier in timber; snowfall exceeds last season's. (C. H. Higbie.)
Lyonsville (Tehama County).—This season's snowfall, 4 feet, has been the heaviest in three years, but there is none on ground at present. (J. C. Hillhouse, P. M.)
Manton (Tehama County).—The snowfall is above average; on ground February 25, 12 inches. (W. E. Hazen.) Markleeville.-The seasonal snowfall is more than double that of last season and the water supply will be much greater. (H. F. Musser, P. M.)
Montague.-The snowfall exceeds that of last season; on ground February 23, 42 inches. Oleta.-Snowfall this season, 4 inches, which melted the following day; last season, none. feet the snow has nearly all disappeared. (Isaac Cooper.)
Placerville.-More snow has fallen this winter than for many years, but there is none on ground at present. The average seasonal snowfall at timber line is 10 inches; this season, 4 feet.
Quincy. This season's snowfall, over 90 inches, is greater than last. age at timber line, 12 feet; above, 20 feet. (W. J. Edwards.)
(H. A. Roterman.) At elevations of 5,000
(J. Leigh Rowley.)
On ground February 27, 12 inches. Aver
Rosewood.-Snowfall last season, 1 inch; this season, 12 inches; none on ground at present. At 4,000 feet elevation the average seasonal is about 3 feet; in January, this year, 6 feet. (H. F. Stivers.)
None on ground at present.
Susanville.-This is the best season since 1895; snowfall double that of last season. (James Branham.)
Truckee.-Snowfall greater than last season's; on ground February 23, 9 inches; average seasonal at timber line 13 feet; above, 16 feet. (C. B. White.)
Weaverville.-Snowfall greater than last season's; none on ground here February 27; at timber line, about 3 feet; average at timber line, 8 feet; above, 10 feet. (A. S. Paulson.)
CENTRAL AND SOUTHERN CALIFORNIA.
Bishop. The season's snowfall exceeds that of last season and the water supply will be much greater. (W. A. Chalfant.)
Independence.-Greatest seasonal snowfall to date for nine years. depth February 26, is 7 feet; average seasonal at timber line, 10 feet.
At 11,000 feet elevation the approximate (John J. McLean.)
Mokelumne Hill.-Season's snowfall greater than last; 6 inches fell during February. In the mountains the fall during February was greater than for several years. Creeks and springs are full. The water supply will be much greater than last season. (C. E. Prindle.)
Summerdale.-The season's snowfall to March 1 is 18 inches more than last season's; 28 inches now on ground. The snow is packed like ice and the ground is very wet. (J. H. Lowry.)
Tehachapi.-Seasonal snowfall greater than last; on ground February 24, 12 inches. Water supply will be greater than last season. (W. H. Knapp.)
Cuyamaca.-Snowfall to February 28, 49 inches, nearly all melted.
last season it reached only the 13-foot level. (G. H. Nelson.)
Campo.-The snowfall exceeds last season's-in the valleys February 10, 6 feet; on the 26th, over a foot on the levels, with drifts 8 to 9 feet deep. Rainfall for season, 22 inches.
Cuyamaca Lake is now at 24-foot level;
San Jacinto.-More snow this season than for past four years; on ground near Strawberry Valley February 25, 42 inches. (C. A. Harper.)
Snow rarely falls along the coast of California; thus at San Francisco snow has fallen only on the dates following since March 1, 1871.
DATES OF SNOWFALL IN SAN FRANCISCO SINCE MARCH 1, 1871.
January 21, 1876.-Light snow fell for 10 minutes.
December 31, 1882.-Heavy snow fell from 11.30 a. m. to 4.20 p. m.; amount, 3.5 inches.
February 6, 1883.—A few flakes of snow fell during the day.
February 7, 1884.-Snow fell at intervals during the day, depth varying from 1 to 2 inches.
February 5, 1887.-Snow fell during the day; depth at office 3.7 inches, while in the western portion of the city it was fully 7 inches deep.
January 4, 1888.-A few flakes of snow fell during the day.
January 16, 1888.-Light snow fell to the depth of 0.1 inch.
March 2, 1894.-A few flakes of snow fell during the day.
March 2, 1896.-Snow mixed with rain fell at intervals during the day.
March 3, 1896.-Heavy snow fell during the night; depth at office at 8 a. m., 1 inch.
Yet during nearly every winter snow may be seen upon the summit of Diablo, Mount Tamalpais, the Berkeley Hills, and ranges of Contra Costa County. Similarly in the southern part of the State during the months of January and February one may walk from the orange groves a comparatively short distance up the mountian sides and find snow. At Los Angeles, for example, in two or three hours one may pass from almost semitropical conditions into alpine conditions. Nearly every pronounced southeast storm during the winter months leaves a generous snowfall in the mountains of the entire State. The amount of snow varies naturally with the elevation, and also varies greatly with different storms. Heavy snow often falls on the ranges in the extreme southern portion of the State. In general the heaviest snowfall is found in the Sierra Nevada and the northern portion of the Coast Range. Elevations of from 3,500 to 5,500 feet apparently have a heavier snowfall than greater elevations.
Tables of snowfall in the Sierra for the last twenty-three years show that from 20 to 40 feet are not unusual annual snowfalls. At Summit there is a record of nearly 60 feet of snow during the year 1894. It is a matter of some difficulty to obtain reliable snowfall measurements. The ratio of 10 to 1, which is used by the Weather Bureau in reducing snow to rain, is but an approximation, and the ratio may be as large as 20 to 1 in the case of dry, fine snow at great elevation, and as small as 3 to 1 in the case of damp snow mixed with rain. A careful measurement at Fordyce, Cal., by Mr. E. E. Roeming, on February 8, 1901, showed a depth of snow as being 36 inches, but when melted it amounted to only 1.70 inches. It is plain that when the temperature is low it takes a large amount of snowfall to make an inch of water. In the case mentioned the ratio of snow to water was 21 to 1, and the writer has been told by reliable observers that in the mountains of California a ratio of 17 to 1 often prevails. On the other hand, at certain points a proper average ratio of snowfall to water would be about 6 to 1. In an article in the Monthly Weather Review for May, 1901, Mr. W. A. Bentley, of Nashville, Vt., who has made a study of snow crystals for over twenty years and has more than 800 photographs, no two alike, states that "the temperature and humidity of the air at the earth's surface is a much less important factor than is generally supposed in determining the form and size of the crystal."