The Weather and Circulation of September 1960*

SEPTENBER-DECEMBER1960 MONTHLY WEATHER REVIEW 353

THE WEATHER AND CIRCULATION OF SEPTEMBER 1960*

Including a Discussion of Tropical Storm Activity

C.F. TISDALE

Extended Forecast Section, US.Weather Bureau, Washington, D. C.

1. WEATHER HIGHLIGHTS lation ol August [I], receded southeastward during Sep- September 1960 will be remembered by residents of the tember to it center north of Scandinavia, where 700-mb. Atlantic Seaboard, from Florida to Maine, as the month heightswere 300 ft. abovenormal (fig. 1). Along with and year of hurricane Donna. This severe tropical storm this development, a gradual contractionof the circumpolar dominatedweather headlines from its det,ection in the vortextook place duringthe month. This circulation tropical Atlantic on September 2 until it became extra- upheaval is indicated by the changes in monthly mean tropical in the Maritime Provinces of Canada on Septem- 700-mb. height departures from normal from August to ber 13. Preliminaryestimates of totaldamage mark September (fig. 2). Sotethe significant heightfalls Donna as the most destructive storm ever to strike the over the polar regions and tlle positive changes over the UnitedStates mainland. The number of fatalitiesand major portions of the United States, Canada, and middle injuries from Donna were slight in comparison with those latitudes of the Atlantic. The resulting mean circulation sustained from other, lesser storms in the past,, and this for September was predominantly one of high index from fortunateoutcome can be attributed in major part to the coast of Asia eastwardto t8he British Isles (fig. 1). widespreadand prompt dissemination of accurateand Planetarywaves were of smallamplit'ude, and the axis timely warnings. of mean 700-lnb. zonal wind speed maxima was displaced Thesudden development of hurricaneEthel in the a substantial distance northof normal over North America central Gulf of Mexico on the 14th was cause forconsider- (fig. 3). Broad cyclonic curvaturecharacterized the able concern to residentsof Gulf coastal sections, especially central Pacific troughand its downstream counterpart those along the southwestern coast of Florida who had overt'he extreme eastern United States. The wave- justendured the fury of Donna.The intensiby of this length between these two systems was long by summer- newtropical threat fortunately decreased quite rapidly timestandards and appears to have been sustained by before it reached the coast and moved inland into southernthe st'ronger than normal westerly circulation. The Mississippi on the 15th. trough normally active along the west coast of t'he United Septemberweather was also highlightedby extreme States was extremely weak, and positive height departures variability, specifically inrespect to the temperature from normal dominated pritct'ically the entire region from regimes exhibited over the country during the course of t8he northwestern LTnited States east,ward to the centra1 the month, as periods of marked cooling alternat'ecl with Atlantic. periods of summer-likewarmth in n~anysections. In Thesimple temperature and fairly well-defined pre- spite of thisvariability, temperatures for thenlont'h as cipitationpatterns for the month of September (fig. 4) a whole averaged near to above normal over practically can be related quite well to the monthly mean 700-mb. the entire country. height, and anomaly pat'terns (fig. I), despite the changes The sharp contrast between record precipitation in tlle in tml-lesepatterns whichtook place duringthe month extremeSoutheast and Northeast and near to record (sect'ion 3). Temperaturesaveraged above normal in drynessin some interior and far western areas was an practicallyall sections of thecount'ry (fig. 4A) under additional highlight of September weather in the United predominantlyabove normal height's. Thewarm tem- Stat>es. peratures in t'he western plateau areas represented a sharp reversal fronl t8he cool weather experienced there during 2. MONTHLYMEAN CIRCULATION AND WEATHER August [I]. Thiswarmth was t~ consequence of upper- level ridge development over the Xort'hwest (fig. 2) and Strong polar blocking, which had dominated the circu- frequentanticyclonic passages in the vicinity of the Rockies (see Chart IX of which kept theregion mainly L'Articles on the weather and circulation of October, November, and Dcccmhcr 1960 [2]) will appear in the Reviewissues for January 1961, February 1961, and March 1'361, in southerly flow at sea level. It was the warmest Sep- respectively. This apparent lag is due to the change in monthly designation of the t8enlber of record Rt Ely, Nev. and the month wasalso Reviewbeginning with thecurrent issue. The calendnr date of publication is not affected. notably 1varn1 insome int'erior sections of California.

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC FIGUREl.--Pvlean i00-mb. contours (solid) and height departures from normal (dotted) (both in t,eris of feet) for September 1960. Note contracted nature of circumpolar vortex with strong zonal flow over middle and high latitudesof North America.

Some warmingwas also experienced incentral portions inated during the month. This was the coolest Septem- of the country under above normal 700-mb. heights and ber since 1889 at Brownsville, Tex. abundantsunshine, with South Bend, Ind. experiencing Heavyprecipitation from Floridanorthwestward to the warmestSeptember since 1933. The cooling which eastern Tennessee (fig. 4B) resulted mostly from tropical occurred in the Middle Atlantic States from August to activitymoving inland during the month. It wasthe September can be attribut'ed to increased cyclonic circu- wet8testSeptember and month of record at Miami, Fla., lation aloft andto stronger onshore flow from the Atlantic. where rainfalltotalled 24.4 inches.Well abovenormal Near to below normal temperatures persisted in most of rainfall in the Xortheast occurred in conjunction with the theextreme Sout.heast and Gulf coastalsect'ions, where passage of Donnaearly in the month, coupled with below normal heights and easterly, anornalous Pow doni- scattwed showers and frontal rains later in t8he month.

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC SEPTEMBER-DECEMBER1960REVIEW WEATHER MONTHLY 355

FIGURE2.-Changes in700-mb. height departures from normal (tens of feet) from August 1960 to September 1960. Subst,antial height falls over polar regionsare especially noteworthy.

FIGURE4.-(A) Departure of averagesurface temperature from normal (" F.) forSeptember 1960. Thepattern is noteworthy forthe prcdomitlance of abovenormal temperatures (shaded) over practicallythe entire nation. (B) Percentage of normal precipitationfor September 1960. (From [ll].)

west8ward to thepdlandle areas of Texas and Oklahoma. Prcdomirmlce of eastcrly anom:rlous flow precluded the possibility of any sustained intrusions of moist, Gulf air northward into the mid-sections of the country, resulting in marld dryness from c1:Lstcr.n Oklahoma northeastward to western New Yorlc. It WIS the driest September and rnontll of record at Akron, Ohio, and the seconddriest Septetnlwr of record at,Detroit, Mich. ant1 Columbia, 110. Almvr normnlheights and strong zorlal flow col- FIGURE3.--?vIean 700-mb. isotachs (in meters per second) for Sep- 1:Lbor:ltetl intjhe production of lit,tle to no precipitation tember 1060. Solid arrows indicatcx axis of wind s1:cc:d maxima, over most of North Utlkota :md Alontarla, whcre rainfall dashed arrows the normal for the rrlontll. The primary axis was deficiencies at Glasgow made this September t'he second north of normalover Korth A4mcrica. Subtropical ridge line is driest of record.Scattered showers, while accounting denoted by solid line cormecting ctntcw of slow wind spccd (S). for the heavy rainfall indicat,cd in north-ccnt~ral Nevada did lit'tle to alleviategeneral drought conditions which have persisted over the State for two years. New recordprecipitation amounts for September were That there was a marked predominance of ant,icyclorlic established at Wilmington,Del., Scranton, Pa., Albany, act'ivit'y in the month's weather, is clearly illustrated by N.Y., and Concord, N.H. Frequent outbursts of frontally the abundance of migratory anticyclones and the almost induced convective activit,ywere resporlsible for twice t,he completeabsence of migratory cyclones inthe United normal precipitationin southern Arkansas and sub- States, except alongext,rerne rlortllerrl border areas (Charts stantiallyabove normal rainfall from Wisconsin south- IX and X [2]). This is in good agreement with what one

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC Unauthenticated | Downloaded 10/01/21 02:41 PM UTC SEPTEMBER-DECEMBER1960 MONTHLY WE:\THER REVIEW 357 would expect under a high index regime with the westerlies Themost inlport'ant weather news of tbe week and north of normal and 700-rnb. heights above norrnal over nlonth was hurricaneDonna. Its entiretrack is given most of the country. in figure 8, and segments corresponding to the period of Below nornlal height's and cyclonic upper flow (fig. 1) each 5-day mean map are reproduced in figure 5. Mov- resulted incorrespondingly below norrndtemperatures ing on a general west-northwestward track (fig. 5A), this and above normal precipitation over most of Alaska during severe storm swept through the northern Antilles late on September. Ternperature ttnorrlalies of as much as -4O F. September 4 and passed just north of Puerto Rico on the and precipit,at'ion ttrnounts greater thm twice normal were 5th, withwinds est'irrlated at 140 m.p.11. 'raking a more recorded insome interior areas of theSt,at'e. This was westerly course on the 7th, Donna scoured t,he northern t,he wet'test September since 1925 at Fairbanks, Alaska. coast' of Cubtr during the 9th and then turned northwest- wttrd (fig. 5B). It crossed the central Florida Keys early 3. TRANSITIONWITHIN THE MONTH on the 10tl1,with winds in gusts up to 175 m.p.11. destroy- The main features of the general circulation over North ing or severelydarnaging 75 percent of the buildings America underwent three major oscillations during t,he throughoutthis section. Turning sharply northward, month of September (fig. 5). There was rapid progressiotl Donna rrloved up along the southwestern coast of Florida during the early part of the rnonth, followed by apparent and passed directly over Ft. Myers at mid-afternoon of retrogression and/or new trough development during mid- the loth, with mind gusts up t'o 121 1n.p.h. recorded there. month, with gradual progression and amplificat'ion again Veering northeastward,the stortn sped across themain occurringduring the latter part of thernonth. Cou- cit'rus growing areas of the State t~rtdrllovcd out over the cornitantwit>h t'hese circulat'ion changes were variations Atlantic on themorning of the llt'h (fig. 5C). Acceler- in the tenlperature and precipitation regimes.These are ating rapidly Donna continued northeastward and again portrayed on a weekly basis in figures 6 and 7, while the enteredland along the extreme southeastern coast of evolution of the circulation is shown by R series of over- North Carolina e1tr.l~-on the12th. The storm spread lapping 5-day mean maps in figure 5. heavyprecipitation across Floridaand southeastern FIRST WEEK coastdsections (fig. 7A).More will besaid about The circulation over the country during the early part Donna's develop~nent andmot'ion in sections 4 and 5. of the week was tnore typical of mid-sulllnler, with troughs SECOND WEEK just off the east and west coasts and tt strong ridge over Progression of the %day mean WBVC train, which began the Mississippi Valley (fig. 5A). 1Jnusu:tll)- hot, hunlid over Xorth Arrlerica duringthe first week, continued weather, which began in middle and nort~hern areas east int,o the second weck with a full-latitude trough supplant- of the Rockies in late August, continued until the 7th or ing t,hc st,rong ridge which had previously dorrlirlat,ed the 8th of September.Maximum temperatures exceeding eastern U'nit'ed States (figs. 5C and D.) Below normal 100' F. occurred at severalstations in theDakot;ts. A temperatures spread over practicallythe whole eastern reading of 94' F. at Lansing, Mich. on thc 7th est:tblislled l~alfof thcl nation under below norrlld 700-rnb. heights, a new record there forso late in the se:tson and some loca- wit'll tcnlperature anotnalies of "Bo F. reported in many tions in New Eng1:land experienced their hottest weiither areas (fig. 6B). Alow of 37' P. at Providence, R.I., 011 of the year. the 17th wits the lowestever recorded there so earlyin Rapid progression of the &day rllean wave trtiirl the season. Above nornlaltemperatures were confined occurredduring the latter part of the week, indirating to the western and southwcsterninterior areas under an end to this period of abnorrrlally high temper'henliddle-Atla~~tic coastal Ternperatures for the week (fig. 6A) were well above sections through eastern New England and the Maritime normal, on the average, over interior California and the Provinces of Canada early in the week (fig. 5C). AFove- Lakes Region underanticyclonic condit'ions and above normal tides, heavy rain, and wind gusts up to 130 n1.p.h. normalheights (fig. 5B). Cooling in the Forthwest' w~smarked the storm's passage intosouthern portions of promoted by northerly anomalous flow over the region. New England during the, afternoon of the 12th. Precipitationin the Midwest and MississippiValley Tropical activity- continued during the week with the occurred in conjunction with a vigorous cold front which rapid developrnent~of hurricane Ethel in the central Gulf t,ruversed these areas during t'he week (fig. 7A). of Mexico on the 14th (fig. 5D). Its position and intensity

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC 358 MONTHLY WEATHER REVIEW SFZTEMBER-DECEMBEE1960

FICIJRE7.-Total precipitation(inches) for the same weeks and FIGURE6,"Departure of average surface temperature from normal from the same source as figure 6. Heavy rains were confined to '1" F.) for weeks inSeptember 1960 centered on the 5-da~7 varioussections in the eastern half of thenation during the mean periods sholvn in maps B, D, F, and G of figure 5, and end- month. ing (A) September 11, (B) September 18, (C) September 25, and (D) October 2. (From [ll].) A'ote themany, and ofttimes marked, reversals in temperature rcgime which occurred during the month. Unauthenticated | Downloaded 10/01/21 02:41 PM UTC SEPTEMBER-DECEMBER1960 MONTHLYREVIEW WEATHER 359 wereestablished on the basis of reportsby t'he Navy advanced eastward to the Lakes Region and amplified to MAMOS (Marine Automatic Meteorological Observ.'1 t'Ion full-latitude proportions, extending from eastern Hudson Station),the first detection of a hurricane by this new Bay southward to the western Gulf of Mexico (fig. 5G). meteorologicalinstrument. This initially severe storm Ridging occurred over the western Plateau, and the low- advanced northward and moved inland with decreasing latitude trough in the Far West receded westward to the intensitynear Biloxi, Miss. during the afternoon of the northern coast of California. 15th, with hurricane force winds observed at but a few Averagetemperatures for t'he weekwere well above scatteredstations in the immediate Delta area. The normal in interior areas of the Far West, with departures stormcontinued to fill rapidly as it movednorthward ranging up to +So F. or more (fig. SD) under anticyclonic during the 16th and 17th, spreading locally heavy rains conditionsand above normal 700-mb. heights.h'ear to from Alabama to the central Ohio Valley (fig. 7B). The below normaltemperatures predominated in the East development and motion of Ethel will be discussed more undercorrespondingly below normal 700-mb.heights fully in sections 4 and 5. (fig. 5G). Three cold air masses advanced eastward across The discovery of tropical storm Florence northeast of northernportions of thecountry during the week (see Puerto Rico early on the 17th (fig. 5E) and its subsequent Chart IX of [Z]). Frosts and freezing temperatures from westward motion along a track closely paralleling that of the Dakotas southward to northern Kansas on the last Donna were additional highlights during the latter part day of the month spread eastward to upstate New York, of the week. New England, and scattered sectionsof Pennsylvania and THIRD WEEK West Virginia by October 2. Little or no precipitationfell over the westernhalf of the The principal circulation features underwent a second nation (fig. 7D) under above nornlal 700-nlb. heights and major change over the country during the third week, as drying,northeasterly anomalous flow(fig. 5G). Heavy a trough developed over the Rocky Mountain St'ates and rainin the Southern Plains was associated with cold- a strongridge again dominated eastern areas (fig. 5E frontal activity early in the week. Generalrains in the and F). Southcast and along the Atlantic Seaboard occurred under Temperatures averaged unseasonably high in the lower st,rong southerly flow of moisture from theGulf of Mexico, Lakes Region and Mississippi Valley (fig. 6C) under anti- with 3 or 4 days of rather dismal weather highlighting the cyclonic conditionsand above-norrnal 700-mb. hcigh t,s. week's activity in these areas. Largeareas east of the Mississippiwere as much as 9O-12' F. warmerthan the previous week. Cooling in 4. TROPICAL STORMS RELATED TO THE north-central sections and the northwestern interior was MONTHLYCIRCULATION associatedwith more cyclonic flow andnear to below normal 700-mb. heights.Rapid drying accompanied the Of the three tropical storms which formed in the Atlantic ridging in the East, with little or no precipitation rerordedand Gulf of Mexico during this September, two developed inmost areas (fig. 7C).Heavy rain in southern Kew to fullhurricane intensity. These figures correspond t'o England occurred in conjunction with cyclonic devclop- meanfrequencies of t,hreestorms and two hurricanes rnent just off the coast early in the week. Moderate to during the past 73 Septembers, but they are slightly less heavy rain in the mid-continent was the result of frontal than the mean Septembcr frequenciesof the past 10 years. activity during the latter part of the week. Precipitutiorl The mean 700-mb. anornaly pattern for t'he month (fig. continued to be very meager in the Far West, where the 1) didnot exhibit any striking similarity to the overall only significant amountsfell in extreme western Washing- patternsfound by Ballenzweig [R] asfavoring develop- tonas a weak cyclonic centerpassed across soutllcrn mentin particular segments of t'hcAtlantic hurricane Vancouver Island early in the period. areas, except for some correspondence to the pattern favor- Tropical storm Florence maintained a general westerly ing development in the eastern At'lantic. This is in itself course and ceased to pose a major threat to the mtlinlwntl of some interest, considcring the diverse areas in which when it passed inland over northern Cuba late on the20th themonth's tropical activity originated; Donna off the and decreasedrapidly in intensit,y (fig. 5E). Themuch west coast of Africa, Ethel in the central Gulf of Mexico, weakenedcenter oscillated sharply southward and t'hen and Florence northeast of Puerto Rico (fig. 8). All three northward across western Cuba during the 22d and 23d stormsdeveloped, however, under a circulation regime (fig. 5F). Remnants of the storm caused hettvy rain over considered most propitious for hurricanes; i.e., during a southeastern Florida and in areas of extreme southeast,ern time of generally high index with t'he westerlies somewhat Alabamaand northwestern Florida during the last two north of normal.This is in good agreementwith the days of the week. proposal byXamias [4] thata northward shift of the westerlies generally is associated with frequent shearingof FOURTH WEEK polar troughs, thus providing a mechanism for maintaining The general circulation underwent its third majoroscil- cold air and cyclonic vorticity in the Tropics after trans- lation over the country during the lastweek of the month. portation from northerly latitudes. Thetrough over the Rocky Mountain States (fig. 5F) Thebehavior of thetropical storms (fig. 8) can be

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC 360 MONTHLY WEATHER REVIEW SEPTEMBER-DECEMBER1960

FIGURE8.-Preliminary tracks of tropical storms during September 1960 in the Atlantic and eastern Pacific Oceans. Open circles and dates indicate 1200 GMT positions.

TOO-mb. map (fig. 1) from sout,hcrrl New England southward to Florida and the eastern Gulf Coast States, imply- ing a high degree of vulncrahilit'y to tropical activity in t~hcsrareas. EASTERN PACIFIC Of interest this month were two tropical storms in tlle eastern Pacific (fig. 8), both of which were of hurricane intensity.Estelle was actually a carry-over from the previous month, havingformed just southof Guatemala on the 29th of August. The track of Est'cllcparalleled the 1IIcan flow (fig. 1) as t'he storm moved ~est-north\~~-cstwarrl and then rccurvcd northward and westwardand dissipated in t,he low-lntitutlc 111ean trough west of Baja C'alifornia on Sept,ernber 9. Ferrlanda tlevelopcd inapproximately the FIGURE9,"Preliminary tracks of tropical storms during September same area as Est'clle, just South of Guatemala, on the Bd 1960 in t,he western Pacific Ocean. Ope11 circles and dates indi- and moved ~\~est-northwcstwardwitti the n~eanAow, cate 1300 C,MTpositions. dissipating west of ccrltral hlexico on the Sth. i;lt,erpreted in terms of the mont'hly mean circulation (fig. WESTERN PACIFIC 1). Donna'strack paralleled very closely the ~ncm Tile most striking aspect of t,he mont'h'stropica; twtivity cont,ours across thesout,tlern Atlantic from western in the westerr) Pacific was t'he complete absence of st'orrns Africa toFlorida. After recurvature, Donna moved of typhoon intensity.Four storms were in evidence sharply northward just, east of and int'he mcan trough duringvarious periods of the month (fig. 9), none of along theeast coast. HurricaneEthel moved north- whichdeveloped beyond the tropicdstorm stage. In northeastward along the mean trough in the central Gulf fwt, t,wo ol the storms, Hest,er :td Gloria (a carry-over of hlexico. Similar motion of hurricanes in relation t'o the from August) were so weak and srllall that their respective mean circulation hasbeen not'ed by Klein [5] and discussed circulations apparently were not discernible for days at a in many articles of this series. The movement of tropical t,irne (dashedportions of tracks in fig. 9). This was in storm Florence southward across western Cuba does not markedcont'rast' to the unprecedented t'yphoon activity fit the 30-day mean patt'ern too well. However, weak which dominated this ares during the previous nlontll [I]. remnants of thestorm did eventually move northward A cornparison of tlle Inem circulation of August [I] east of the mean trough in the Southeast. Kote also the witht'hat of Sept'ernber (fig. 1) suggeststhat the whole st,ronp easterlv. anornalous flow corn~onentson the mean Datternin t'he western Pacific shiftedsout'llward and

Unauthenticated | Downloaded 10/01/21 02:41 PM UTC SEPTEMBER-DECEMBER1060 MONTHLY WEATHER REVIEW 361 eastwardabout loo of latitudeduring September. The Donna,including ageneral summary of thestorm’s persistent Low over Formosa in August, which served as track,major features of t’he storm in seriously affected a sink for the cyclonic vorticity of t’he many t’yphoons, islandand continental areas, plus somecomparisons of mightconceivably have been absorbed northward into variousforecasting techniques in their application to the westerlies early in Sept’ernbcr. This could have con- Donna, is beingprepared by Haggardand Cry of the tributed to the development of the mean trough a!ong the U. S. Weather Bureau*. coast of easternSiberia. The subtropical ridge was Dunn [lo] hasindicated that trailing, stationary, or stronger than nornlttl in the west-central Pacific(+ 180 f‘t,., fractured portions of old polar troughs may provide the fig. 1) and extended st’rongly westward south of Japan to initialconcentration of cyclonic vort’icitynecessary for eastern China. The marked southeasterly and convergent hurricaneformation. This cert’ainly appeared t’o be the anomalous flow south of Japan in August (see fig. 1 of [lj) case inregard to the development of hurricaneEthel was replaced by a northeast’erlyand strongly divergent justeast of thet’railing, southern portion of themean anoma!ous Aow during September. polar trough in t’he central Gulf of Mexico on September Tropical storms Gloria and Irma developed some dis- 14 (fig. 5D). The st’orrnmoved north-northeastward tance east of the Philippines and moved west-northwest,- along this trough, entering t’he coast near Biloxi, Miss. on ward with the mean flow. Both storms eventuul1~-dissi- the 15th.The st’orrn continuednorthward with rapidly pated in the same generalarea of the South (lllintL Sea diminishingintensity, eventually dissipat’ing thein (fig. 9). Hest’er and Judy were relatively weak and short Tennessee Valley on the 17th. lived storms which deve!oped southeast of Japan. Both Tropicalstorm Florence developed from an easterly stormsmoved northwest’ward and were absorbedinto wavewhich moved throughthe Lesser Antilles during strong cold-front’al systems which had nlovetl southenst- the l6t,h. The circulat’ion was first det’ected nort’heast of wlrd from Japan. Puerto Rico on the 17t’h, and t’lle storm moved westward with the mean flow, entering land in northwestern Cuba 5. TROPICAL STORMS RELATED TO during the 21st’ wit’llout ever attaining hurricane strength THE5-DAY MEAN CIRCULATION (fig. 5E). Weak remnants of t’hc storm oscillat’ed south- The relation of the tropical st’orms of the Atlantic to wardand northward itcross westernCuba to Florida the &day mean circulnt’ion is deserving of special att’en- from the 21st to t’he 24th near a mean t’rough in an area tion,especially since t’he paths of thestorms are often of very weak gradient (fig. 5F).This track may have influenced by short’-period means. been influenced more by prevailing surface conditions in Theexact conditions which led t’o the inception of the area t’han by mean circulation features. Donna off the western coast of Africa during late August REFERENCES can only be surmised due to the paucity of data in this 1. L. P. Stark, “The Weather and Circuiation of August 196GA particularsegment of theAtlmtic. It is quitelikely, MonthDominated by a CirculationReversal,” Monthly however, that the initial disturbance was in the form of Weather Review, vol. 88, No. 8, Aug. 1960, pp. 286-293. asevere West African squall line of thct’ype described 2. U.S. Weather Bureau, ClimatologicalDala-National Summary, ~ol.11, No. 9, Sept. 1960. (in press) byRegula [6]. The firstadvisory on Donna was issued 3. E. M. IMlenzweig,“Relation of Long-PeriodCirculation on September2 with the storm some 700 miles east of Anonlalies to Tropical Storm Formationand Motion,” the Lesser Antilles and already of full hurricane propor- Journal of Meteorolcgy, vol. 16, KO. 2, Apr. 1959, pp. 121-139. 4. t’ions. Donna rnoved 011 a generalwest~-northu~estward J. Xamias, “Long-RangeFactors Affecting the Genesis and Paths of TropicalCyclones,” Proceedings o,f the UNESCO track with the mem flow, arriving in the extreme eastern Symposium on Typhoons, 9-19 November 1954, Tokyo, 1955, Bahamas on the 7th (fig. SA). Note the slowing down of pp. 213-219. the storm’s forward progressfrom the 5th 60 t’he 7th 5. R. H. Klcin,“The Weather and Circulation of Junc 1957- andt’he t’urn to a Inore northwesterlydirection as it Including an ilnalysis of Hurricane Audrey in Relation to approachedthe mean t’rougll off theeast coast. It was theMean Circulation,” Monthl?]Weather Review, vol.85, unfortunatethat the general circulation underwent its SO.6, June 1957, pp. 208-220. 6. H. Regula,“Tornadoes and Pressure Variations on the Rest firstmajor oscillation of themonth at this time when Coast of Africa,” Annalen der Hydrographie und Maritimen conditions appeared rather propit’ious for possible north- Mefeorologie, vol. 64, Jan. 1936, pp. 107-111. wardrecurvature of the storm well off thecoast. As it 7. Ti. Butson, “Hurricane Donna in Florida,” Weatherwise, vol. 13, was, rapid progression of the 5-day mean waves occurred, No. 5, Oct. 1960, pp. 210-212. with the trough off the coast shearing and moving to the 8. A. V. Hardy, “Hurricane Donna in North Carolina,” Weather- wise, vol.13, No. 5, Oct. 19€0, pp. 213-214. central Atlant’ic, and the strong High over the Mississippi 9. J. K. MeGuire, “Hurricane Donna in thct Xortheast,” Weather- Valley advancingeastward to the coast and effectively wise, vol.13, No. 5, Oct. 1960, pp. 215-217. bridgingthe gap north of thestorm (fig. 5B).Donna, 10. G. E. Dunn, “Tropical Cyclones,” Compendium of Meteorology, accordingly,turned again to amore westerly course, American Meteorological Society, Boston, 1951, pp. 887-901. recurving sharply northward across Florida on the 10th 11. U.S. WeatherBureau, WeekZty Weatherand Crop Bulletin, NationalSummary, vol. XLVII, Kos. 37-41, Sept. 12, 19, and up along the full length of the Atlantic Seaboard in 26, Oct.. 3, 10,1960. advance of the full-latitude trough which settled in over *Shorter accrnnts of the storm’s ~.msa::e tl,Iouy!l verins parts of the Vnited States the East (fig. 5C). A rather intensive report on hurricane have hem [~lblishul[i, 8, 91 Unauthenticated | Downloaded 10/01/21 02:41 PM UTC