NOVEMBER,1917. MONTHLY WEATHER REVIEW. 56 1 SECTION VI1.-WEATHER AND DATA FOR THE MONTH. WEATHER OF NOVEMBER, 1917. seasonal average from the lower Lakes Region, and the lower Ohio and lower Mississippi Valleys eastward. P. C. DAY,Climatologist and Chief of Division. Over most of the Missouri Valley and central and north- PRESSURE AND WINDS, ern Great Plains, the temperature for the month averaged from 6 to 15 de-rees above the normal, while in some The distribution of the mean atmos heric pressure of the Canadian provinces to the northward the positive departures were 20 de-rees or more. In North Da- over the United States and Canada, anCf the prevailing direction of the winds for November, 1917, are graph- kota and ortions of tte adjoining States it was the ically shown on Chart VII, while the means at the warmest Jfovember in 25 years, and November was several stations, with the de artures from the normal, warmer than October. The temperature averaged over are shown in Tables I and &I. 3 degrees a da below the normal in Florida, the ex- ng of the month the pressure was treme eastern iakes Region, and along the immediate relativelyAt the hig throughout the United States, but in Atlantic coast. the Canadian Northwest it was slightly below the sea- PRECIPITATION. sonal average. High pressure continued in most sections throughout the first decade, except for a few days nbout During the first and second decades there was much the middle of the period, when it was relatively low suilsliine and very little reci itation, except about the in the western half of the country. middle of the first decaa2 e, w en rain fell in the Pacific decade, except for the occasional States and Nevada; and during the latter part of the across the country, the ressure second decade widespread, but moderate, rain fell from above the average. At tge the Central Plains southward and throughout the Cotton lower pressure prevailed Belt. Tho htfew days of the third decade were country, but in a few da there was a return to higher marked by considerable rain or snow in the Lakes ,which continuer until near the end of the month, Region and Northeastern States. This was followed readinKswhen ower pressure oversmad most sections of the by generally fair weather in most sections until near . The month close ct with relatively low pressure the end of the month, when moderate recipitation fell out central districts and in the far Northwest; in the far Northwest and from the Plains Eegion eastward. it was near the normal.. The recipitation for November, as a whole, was For the month as whole, the barometric pressure unusu airy light, the month being am0 the driest in all districts except in the Novembers ever known in many districts. %om north- the Canadian Provinces to ern Oklahoma and central Missouri northward there was it was below the seasonal decidedly little rain or snow, exce t in small areas. The departures were generally not large, al- Most of the Rocky Mountain and f:lateau States had thoug in the upper Lakes Region and portions of the less than half an inch, while in racticall the whole of averY- Arizona and portions of the azoining Btat- no pre- Rocky Mountains they were rather pronounced. cipitation occurred during the entire month. In the The distribution of the Hrmrs and LOWS resulted in revailing northerly winds in the Atlantic and eastern Pacific States the amounts were generall below the nor- 8ulf States and portions of the upper Lakes Re-ion mal, although from 6 to 8 inches occurreK in the extreme while southerly winds were frequent in much of? thi western portions of Washington and Oregon, as well as great central valleys. Elsewhere variable winds pre- in northwestern California. vailed. snozofau. TEMPERATURE. During November the snowfall was unusually light, The month opened with temperature below the normal althou h moderate amounts fell at oints in the u per in all districts, except arts of the Northwest and the far Lakes Begion and to the eastward. fn the districts Prom West. About the mixdle of the first decade there was the Rocky Mountains westward but little snow appears a eneral warmin up and mild weather was the pre- to have fallen, even in the high mountains. vakg condition fhroughout most of the country until the middle of the month. Durin the next few days RELATIVE HUMIDITY. frost occurred in the interior of 8alifornia, and it was The relative humidity was above the average in the cool in the Cotton Belt and Middle Atlantic States, northern part of the country, escept in portions of the and some frost occurred in the South Atlantic and u per Missouri Valley, where it was generally below. eastern Gulf States. Durin the last decade of the Aewhere the atmosphere in most sections was rela- month it was colder than t %e seasonal average.in the tively drier than the normal, especially from the eastern lower Lakes Region and the North and Middle Atlantic States westward to the Rocky Mountains. States and about normal in the Cotton States, while Gulf elsewhere it was warmer than normal, especially in the middle and upper Missouri Valley, where it averaged GENERAL aummm. about 15 de ees above the seasonal tem erature. November's weather was enerally favorable for out- The mont!f. as a whole was warmer tl! an normal in door occu ations in practicafi y all sections of the coun- most central and western districts, and cooler than the try and aIf Fall work progressed in a satisfactory manner, 33848-1+3 Unauthenticated | Downloaded 09/25/21 01:27 PM UTC 562 MONTHLY WEATHER REVIEW. NOVEMBER,1917 exce t where delayed b the scarcity of labor. The 38.32 inches on the 16th, and the highest, 30.40 inches, rain all waa much below t1 e normal in practically aU the on the 37th. winter-wheat-growingP area and the dr weather delayed The following table gives for a number of selected the germination .of lute sown rain ani in solne sections &degree s uares the average pressure for each of the revented plowing and seed ing, but conditions were three deca1 es of the month, as well as the hi hest and favorable for drying corn. The hard winter truck crops lowest individual readings reported during tf e month were generaU in good condition. dedry weather was within the respective squares. unfavorable Por pastures and ranges, particularly in the Southwest, and stock was in poor condition. The Prt-ssure owr fhe North At2anl.k durilcg Xownibw, 1916, by 6degree weather was favprable for the citrus and raisin crops, squares. but strawberries in Florida needed rain. _..-.___-- I -7- Extremes. Average acnrlnziluted departures for Novembm, 1917. Position of &degree Decade means. square. -._ ___-____ Highost. I Temperature. Precipitation. Cloudiuess. e$$!. Latitude Longitude. I. III. Date. Data. .. .. llI - 11. 2; i I _- I 1-1- --- I Indrer. Now. w-65 Ti 28.81 27 wfi N 28.70 6 5.5-H) N 28.79 17 5.5-RU N 55dl) N 4.26.7680 48; .3~-55N 29.28 10 BJ-55 N 29.18 17 &55 N 28.22 16 jrW5N 4.70 16 3M.5 N !a80 I9 I st. I =F. 1 OF. Ins.0.85 -2.MIIM. I -3.10In,. 1 -1.6 P.c;~ -6 4.W) N 28.92 24 New Englmd,. .. 36. i[-3.4,-1i. I 1 "4 I 4540 29.40 1421 N Middle Atlaupr.. .. 41.71 -2 5:-13. O.Hi -2.20 -3.50 4.4 -1.0 -5 45-50 N 28.86 18 South Atloutl~'.... .. 61.61 -?:SI -2. 0.70 -?.90l-l0.a-l( 3.L' -1.2 -4 40-45 N 29.1u 8 48-15 N 29.10 4 .35-40 N 29.35 9 30-35 N 29.92 3 West Gulf. .. .. -.. .. --I -25-30 N ae. 90 8 15-20 N 29.76 13 ObioVallcymdTm-/IESSee ._.-......... 44.0 -0.6 -19. 1 0.3-0.30 +2.20 5.1 -0.5 0 Lower Lalies... .... 36.1 -3.0 -m. 0.821-1.601iml-zml +o.ml-3.90 0.016.11 -1.31-1.0, GI52 +I+2 Upper Lakes. -... 38.1 +I.$ -30. The mean and extrenie values presented in the above table are based on the daily pressure values determined b inte olation for each square in the daily synoptic cZT arts o the North Atlantic Ocean compiled by the Northern slow .._._..40.7 +s. 7 -10. Marine Section of the Weather Bureau. Hid& 810p"- ...____.48.0 +6.? -2. o.=~-o.RI~O.l"-O.40 -,.In1-!.W 3.714.4 -0.7-0.31 -5 0 Southems ope ....... 53.3 +4.P +8. 0.2;-0.60 -8.10 2.9 -1.5 -15 , southernPlatesu.... 52.9 +4.0 -1. 0.M-0.80 -?.70 1.4 -1.4 45 --I QALES. Mlddle Plateau. -.. 4?. 8 +S. 2 -21. Northern Plateau.... 43.4 4-4.8 -7 0.51l.J-d44 -0 40 -2.70-2.34 -d 4 1; The number of all s and their relation to the normal 4.43-?.40'-11.00 6.i -0.9 31 0 differed considerah in the several portions of the ocean, 1.X-1.40 -9.40 4.R +0.1 (21 -3 fy 0.3?-1.00li -4.30 Ill3.1 -1.7 661 -1 as north of the 50th arallel and in the waters adjacent to the greater part oP the Anierican coast they were re- ported on comparatively few days, while over a large WEATHER COND~~IONSOVER THE NORTH ATLANTIC DURING NOVEMBER, 1916.