1116 MONTHLY WEATHER REVIEW. DECEMBER, 1909
Climatological Data for December, 1909.
D I S T R I C T No. 1 1 , C A L I F O R N I A .
Prof. ALEXANDER G. MOADIE. Dhtrlct Editor.
The month was one of typical winter weather in this portion
of the Pacific coast. There were frequent and heavy rains, and at intervals heavy frosts. There were more than the
usual number of frosts and the temperature on several niorn-
ings fell below the danger point in the citrus fruit belt. The
mean temperature of the State as a whole was nearly 3 " helow
the normal, but in the southern counties a better idea of the
general character of the month can be had from the number of
temperatures below the freezing point that were recorded even
at points close to the coast. Low morning tempcratures at points in the interior are, of course, not infrequent during the
winter months, but coast temperatures as a rule seldom fall below 32". The precipitation was much above that of a normal
December. In a general average for the State the rainfall,
including melted snow, was about 50 per cent in excess of that
of a normal month. The precipitation varied from nothing at
points in San Bernardino County to over 20 inches in the north-
ern coast and mountain sections. The greatest snowfall re-
corded was at Tamarack, the monthly total being 92 inches, and the next greatest was 76 inches a t Fordyce Dam. At the
beginningof the month thesnow covering, at elevations of about!
7,000 feet and north of the 35th parallel, was fairly represented
by a depth of 2 inches, while at the close of the month there was
an approximate depth of 45 inches. There was not much nielt-
ing and but a moderate run-off.
Comparing the present month with previous years, the fol-
lowing figures give the mean temperature: 1897, 44.4"; 1898, 44.4"; 1899, 45.8"; 1900, 47.3"; 1901, 47.4"; 1902, 46.6";
1903, 48.0"; 1904, 47.2"; 1905, 45.3"; 1906, 47.3"; 1907,
48.3"; 1908, 43.2"; 1909, 43.3". The month was there-
fore about as cool as the previous December and much
cooler than any other December during the entire period.
During the first decade temperatures were for the most part
normal or slightly above, owing to the prevalence of southerly
winds and the recurrence of barometric depressions over the northern half of the Pacific slope. During the second clecadc
there was a noticeable change in pressure distribution, with a slow-moving or stagnant anticyclonic circulation. The winds
were mostly from the north, and at times, as on December 13
and 18, strong. Frosts were frequent during this period,
although the afternoon temperatures would sometimes rise to
70". The period lasted until the 19th. One of the niost in-
teresting dates of the m0nt.h was December 18, when a st-rong
north wind, commomly known as "Santa Ana," thrashed the
trees and fruits, whipping off, it is estimated, about 10 per cent of the oranges and lemons. This was followed by heavy frosts.
At San Diego the temperature fell to 36" on the morning of the
19th, which is a very low temperature for that station and indi-
cating temperatures below freezing in the lemon and orange
districts back from the coast. Ample warning was given to the
fruit interests. The third decade was one of unsettled weather,
due to the passage southward of several minor depressions, the month closing with a well-markecl storm which in the southern
coast counties, by reason of the heavy rains and washouts clue thereto, caused much damage. The rains continued into the
first few days of January, resulting in floods in southern Cali- fornia. The property loss was estimated to be in the neighbor-
hood of $100,000. The Santa Ana River overflowed its banks
and much celery land was inundated. Transportation and
power companies suffered and there was considerable inter- ruption of general and local passenger service. It was said that
the rainfall in the San Gabriel Canyon, as measured by the
power company officials, was 10.50 inches in 26 hours and was the heaviest recorded in a period of 15 years. Considerable
damage was done to telegraph and telephone wires in all sec-
tions. The following heavy 24-hour rainfalls were reported on the 31st: Azusa, 4.40 inches; Claremont, 2.85; Glenn Ranch,
3.89; Los Angeles, 2.15; Lowe Observatory, 8.50; Lytle Creek, 7.50; Mono Ranch, 4.64; Newhall, 4.46; Ojai Valley,
4.87; Ozena, 4.00; Pasadena, 3.28; Rialto, 6.70; San Bernar- dino, 2.90; Santa Barbara, 2.30; Sierra Madre, 3.85; Surrey,
4.30; Upland, 4.00.
The following notes on conditions during December are con-
tributed by cooperative observers:
Arturn.-TIie rain on the 31st, ending January 1, amounted to G.11
inches, and caused aevere floods. The San Gabriel River was a ra ing tor- rent. Electric tracks were waahed out, one span of the county brifge went out, and a small bridge on the Santa Fe Railroad went down with the engine.-Alfred P. Grwth. Ditrhnm-The snowfall on the 5th wag estimated to be G inchw, and re-
mained on the ground in sheltered places 3 or 4 days. The temperature was unusually low.-R. W. Durham. Indepe/tdence.-December was the coldest on record at this station, with
a mean monthly temperature of 25.9". Old residents state that on Decem- ber 3, 1S73, there was a cold wave here with tem eratures equally as low as the current month and a snowfall of about 4 f&t. The ground, where free from snow, is frozen to a depth of from 10 to 15 inches. This is unprere- dented and unlooked for. The water mains are placed at a depth of 12 to
1s inches, and half the town is without water from the frozen mains. Owens River is not frozen over, but ponds and lakes are entirely frozen over.-E. M. Brooks. Illadditie.-The month has been unusually cold and the ground is frozen 19 inchej deep. Ice is being cut 14 inches thick.-J. H. Williams. AZagnlia.-The winter weather to date has been much more severe than for several years past, with more r d n and snow.-A. F. Rite. OrZnnd.-Progress on the Orland Project for the month has been satisfac- tory. All contractors are at work on the distribution system. A small force is at work on the south main canal, enlarging and building concrete structures. TheEast Park dam is at an elevation of 27 feet above the creek bed.-M. E. Ready. Sio/nmrd&.-The heaviest rain on record at this station for any 24 hours, 7.53 inches, fell on the 31st. The total precipitation for the year 1909 is 89.16 inches.-J. H. Lo7~ry.
Three Riwrs.-On the morning of the 9th the water in the river was higher at this point than it has been for 18 years.-E. D. Barton. Ticlore.-There were no killing frosts durin the month, although the temperature fell t o 30" on the 4th and 15th, a n i 32" on the 3d, 16th, and
Very severe winter conditions have also been esperienced on the Klamath Project. Fortunately we never contemplate much work at this oint dur- ing the winter months, as there is always more or less frost. We [ad, how- ever, planned to do a good deal of work along the southern shore of Tule Lake, using a large power launch as the principal means of transportation t o this remote locality. Tule Lake seldom freezes over; but I understand this year a large part of the lake has frozen over and operations have been so far rendered impossible. Severe weather conditions have also been reported as far south as Fallon, Ncv.-E. G. Hopson, Siipersisitlg Etigitieer.
17th.-John Tzlohy.
ESCESRIVELY HEAVY PRECIPITATION I N CALIFORNIA DURING 1909. Inches.
Bear Valley, Nevada Co.. ................. Blue Canon.. ............................ Bowmans Dam ........... ........... .113.S5 Branscomh. ............... Brush Creek.. ............. Camptonville .................................. ,136.38 Deer Creek.. ............ Delta. .................. Downieville .................................... .101.&1 Fordyce Dam.. ............... ............... .125.28 Head Dam.. ................ .............. ..loo. 14 Inskip ......................................... .134.68 Kennett ........................................ .115.92 La Porte.. .................................... .ldl. 40
Magalia ......................................... 150. 62 ilfonumental ................................... ,163.64
Nimshew. ...................................... .103.26 ............................ .117.61
Stirling City.. ................................. .1M. 63 Upper Mattole.. ................................ .121.79 West Branch .................................... .119.45 Woodleaf ...................................... .125.2Se The greatest previous recorded annual precipitation was 139.20 inches at Monumental in 1907.