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 , 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 °ree 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 °ree Decade means. square. -._ ___-____ Highost. I Temperature. Precipitation. Cloudiuess. e$$!. . 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 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. territory in mid-ocean they were considerably more OCEAN numerous than usual. The greatest number occurred on The data presented are for November, 1916, and the 5-degree square between latitude 45' to 50' and comparison and study of the same should be in connec- longitude 35' to 40°, where they were reported on 13 tion with those appearing in the REVIEWfor that month. days, a percentage of 43, while the normal percentage Chart lX (xLv-111) shows for November, 1916, the for that square is 18. averages of pressure, temperature, and the prevailing On November 1 and 2 there was a LOW of moderate direction of the wind at 7 a. m. 75th time intensit between the 40th meridian and the American (Greenwich mean noon) , and notes on the locations and coast, tg at was attended by moderate gales over a limited courses qf the more severe storms of the month are area. included m the following summary. On the 3d the southern limits of a second depression extended to a oint near latitude 53', longitude 20'. PRESSURE. By the 3d this YI ad develo ed in a marked degree, the center now being near Blacf -sod Point, on the west coast The distribution of the avera e pressure for the month, of Ireland, where the barometer reading was 28.53 as shown on Chart IX,differed But little from the normal inches. No specially heavy winds were reported from over the greater part of the ocean. The North Atlantic of the few vessels in the vicinity, as the highest and contmental HIC~IISwere practically normal in posi- %city recorded was 40 miles an hour. tion, extent, and intensity, but the Icelandic LOW, with On the 4th this disturbance wm central near latitude a mean pressure of 29.48 inches, was considerably south 48' longitude 13' W., the pressure having changed but of its usual position. lit& since the revious day, while the storm area had The pressure changes from day to day were unusually increased slightP y in extent. This LOW recurved toward large in some localities; the greatest range occurred in the north and on the 5th the center was near Holyhead, the square between 50'-55' N. and En land, the lowest barometer reading being 28.58 mches, 20'-25' W., where the lowest barometer reading was wit1 northwest gales of from 40 to 65 desan hour over Unauthenticated | Downloaded 09/25/21 01:27 PM UTC NOVEMBER,1917. MONTHLY WEATHER EEVIEW. 563 the region between the 20th meridian and the European tensity, and norther1 gales of 60 miles an hour were en- coast, and the 45th and 55th parallels. countered in the Guls of Mexico. The northern dist;urb- On the 5th a second LOW, I on Chart IX, was central ance remained in nearly the same position as ou the two about loo east of St. Johns, N. F., several vessels in the revious days, strong gales with hail still raging over a southerly quadrants having encountered moderate west- Parge territory. The center of LOW IZ did not appear on erly gales. the chart after the 15th, although on the 16th moderate phe European LOW continued in its northerly course, gales occurred in tlie'eastern part of the Gulf of Mexico and on the 6th surrounded the Shetland Islands, the wind md off the eastern coast of Florida, attended by baro- velocities evidently having moderated since the revious metric readings of from 30 to 30.3 inches. The northern day, although few vessel reports were received ?rom tlie LOW moved rapidly toward the east, and on the 16th was vicinity. central near latitude 55O, longitude 23 J; with increased Low Imoved rapidly in a due easterly direction, and on intensity, the minimum barometer reading being only the 6th the center was near latitude 47O, longitude 27") 28.20 inches, the lowest recorded during the month. and winds of gale force prevailed between the 20th and Gales of from 40 to 70 miles an hour swe t over the ter- 45th meridians. This disturbance curved sharply toward ritory between the 45th and 60th paralle I?s, and the 15th the northeast, and on the 7th was in tlie vicinity of the and 35th meridians, hail also bein reported by a number north coast of Scotland. Reports of gales were received of vessels. The LOW moved rapid Py toward the north aud from a number of vessels scattered over a large territory on the 17th the center with a minimum of less than 28.80 between the 58th meridian and tlie European co.wt, ex- inches was a parently somewhere between Iceland and tending as far south as the 45th parallel. Low I nioved , aY though the center could not be plotted on slowly toward the northeast during the nest 2.4 hours, as account of lack of observations. On the same day a hgh shown on Chart IX, aud on the 8th conditions of wiiirl and with a crest of 30.24 inches was central near Boston, and weather were practically the same as on the previous day, while the centers of these areas were a long distance apart, although the storm area had diminished in extent, and strong ,odes with hail and snow prevailed over that part hail waa reported by oue vessel. of the intermediate tenitor between the 40th and 50th On the 8th a second well-developed LOW was ccntrnl parallels and the 35th au2 55th meridians. From the near latitude 44O, longitude 44"; the barometer readiii lSth to the 21st a LOW covered the waters adjacent to the was 28.85 inches asd moderate to strong gales prcvailt.2 European mast, between the 45th and 60th arallels, but between the 33d and 60th meridians. no heavy winds were reported in the imme2 iate vicinity. On the same day one vessel reported a northcasterly On the 18th a HIGH with a crest of 30.33 inches was cen- gale of 60 miles an hour off the southern coast of Cuba, tral about 300 ides southwest of the Azores, while the although there was only a slight depression with a mini- LOW on that day was in the vicinity of northern France, mum reading of 29.77 inches near latitude 15", longitude the minimum reading being 28.64 inches. The steep 78". On the 9th neither LOW 1 nor tlie West Iutlies dis- gradient between these two areaa was responsible for turbance appeared on the chart, while the second LOW of the northwesterly ales that prevailed over the central the 8th was centrd near latitude 4S0,longitude 3S0, and ortion of the sout7 iern steamer lanes, where snow and winds of gale force prevailed over a large area, between Flail were also reported. On the 21st and 22nd there the 30th and 52d arallels, and the 25th and 55th merid- was a LOW of sli ht intensity near latitude 50°, and ians. On the lot{ this disturbance began to fill in, and longitude 37O, anf on the former date a few vessels in the storm area had contracted in extent, although a num- the southwest quadrants reported moderate gales. ber of vessels as far south as the Azores still encountered On the 34th a well-developed LOW with a nlinimum moderate gales. 25.58 inches covered a large part of the Prov- On the 12th a LOW, I1 on Chart IX, covered the greater readillFince o ,Of strong southerly and southwesterly gales art of the region between Jamaica and Central America. prevailing as far south as the 35th parallel, between $his depression was present in the waters during nearly all the 60th and 70th meridians, while only nioderate winds the previous portion of the month, although it was of were recorded in the immediate vicinity of the American slight intensity, and accompanicd by light to moderate coast. This LOW evidently nioved rapidly toward the winds. On the 12th, however, it increased in force, as north, although it was iiii ossible to plot its center on the barometer fell to 29.66 inches, although there was no the 25th, on account of lacpc of observations. Moderate material increase in wind velocity. On the same day a gales were still encountered by a number of vessels second disturbance was central near latitude 48O, longi- alon the American coast, between the 34th and 43d tude 42O, and moderate gales accompanied by hail pre- par a5els, inteispersed by reports of winds of not over vailed over a limited area in the southern quadrants. 35 ndes an hour. Low II moved slowly toward the northwest and on the The conditions during the remainder of the month 13th its center was near Swan Island; the iowest baro- were comparatively featureless, as no LOWS of marked metric rea- was now 29.60 inches, but there was little intensity appeared during that period, although on the cbangein theconditions of wind and weather since the 12th. 30th a few vessels near the 50th parallel and 40th The northern LOW moved about 6" due east durin the meridian recorded northwesterly ales of froni 40 to next 24 hours, and while the barometer had risen sligB tly, 60 ndes and hour, attended by h2and snow. the storm area was somewhat larger on the 13th than on the previous day, moderate gales with hail and snow still TEYPERATTJEE. prevadmg. Low I1 continued on its slow northwesterly course, with little change in intensity. The northern LOW The average monthly temperature of the air over the remained practically stationary in osition and lost in ocean adjacent to the American coast, and in the nor- force, although on the 14th a num73 er of re orts were thern part of the Gulf of Mesic0 ranged from 2 to 7 degrees received from vessels between the 37th and 57t9 parallels, above the normal, while along the European coast they winds of gale force, with hail and snow. Low were froni 2 to 4 degreea above. The departures were also indicatYI1 curve sharply toward the north, and on the 15th the slightly positive in a narrow belt that extended across center was near the west end of Cuba, with increased in- the ocean between the 35th and 40th parallels, while Unauthenticated | Downloaded 09/25/21 01:27 PM UTC 564 MONTHLY WEATHER REVIEW. NOVEMBER,1917 over a large portion of the waters north and south of PRECIPITATION. that area the temperatures were either normal or slightly below, the same condition holding true in the The number of days on which hail was observed was southern division of the Gulf of Mexico. apparently larger than usualJ and in the square between The following table gives the de artures for the latitude 45"-50°, longitude 40°45", where the maximum month at a number of Canadian an U. S. Weather amouiit occurred, it was reported on every da from Bureau Stations on the Atlantic andB Gulf coasts. November 12th .to 15th, inclusive, and again on t i!l e 17th and 23d. In the regions immediately north, east and F. F. west of this s uare, it was recorded on from 2 to 3 days, St. Johns, N. F ...... -2. R Norfolk, Va ...... +l. 3 gdney, C. B. I ...... -1. 1 Hatteras, N. C: ...... +O. 7 while east of Bt e 30th meridian there was none. alifax, N. S ...... -0,9 Charleston. S. C ...... +l. 1 Snow was reported on three days in the following East ort, Me ...... -2. 6 Key West, Fls ___..___._..-0.1 squares: Between latitude 40O-45" and longitude 60"- PortLd, Me...... -1.0 Tam a, Fla ...... +l. 4 65"; latitude 50"-55" and longitude 35"-40°, and also in Bmton. Mars...... +l. 4 ~o&. Ala ...... +2.5 Nantucket, Mass ...... -0. 7 New 0rleane.La .- -.------+2.0 the territoi between latitude 40O-45" and longitude 40' Block Island. R. I...... -0. 3 Galveston, Tex _._.._._..___0.0 arid 50". gone was recorded in the vicinity of the Eu- New York, N. Y...... +O. 8 Corpus Christi, Tex ...... -0.3 ropean coast, or over the eastern section of the steamer The lowest temperature recorded during the month wn.s routes. 27", and occurred on a number of different da s over the Ilrim& of 50 inilea per bur (22.4 m.fsec.) or over during November, 1917. waters adjacent to the east coast of Newfoundmid, while the highest reading for the same region was 46". The sea~onalfall hi temperature was quite marked, especially Station. Data. inthe hi her latitudes, where the average for the lust dec- - ...... -. .II Nia./hr MiaJhr. ade of tfl e month was considerably lower than usual. 2650 nw. New York N Y 18 58 nw. 3 52 W. NorthFI&,Wwli. 2 b0 SB. FOG. 21 5.1 UW. Do ...... 4 Bae. 22 52 ne. Do ...... 27 52 s. 21 66 n. Pierre S Dak..... 21 60 nw. 011 21 w nw. St Jo& h Mo .... 21 M nw. The number of days which fog occurred was much st'~auP& .... 21 51 nw. below the normal over the entire ocean. It was re orted 5 58 nw. si0ux~ItyIowa.. 50 nw. a manw. Tatoosh island, on 3 days, erceiita e of 10, off the banks of NeJ ound- 852nw. Wasll ...... 20 58 8. land where t15 e norm percentage is from 30 to 35. In 110 other s uare was it observed on more than one day, and nearly % of the steamer lanes were entirely free.

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