20 MONTHLY WEATHER REVIEW

Weather Note TORNADOES NEAR NAGS HEAD, N.C., IN MAY ANDJUNE 1960 FRANK B. DINWIDDIE 1 Nags Head, N.C. [Manuscript received July 18, 1960; revised NovemberI4, 19601 1. TORNADOES ON MAY 11, 1960 A family of suspended funnel and accompanying pendantswas seen at NagsHead on May 11, 1960, between 1520 and 1530 EST. Surfaceconditions at the t,ilne were: wind light and variable, from directions east,, sout'h,and west. Shortly after the episode the wind became SSW about 10 1n.p.h.and continued thus. Sta- G t'ion pressure was 29.82 in.mercury, and rising slowly, temperature 70" I?., steady, dew point 56" F., and relative humidity 64 percent.occurrence Before the of the sv t funnels,cumuli moved from the peninsula between Pamlico andAlbelnarlc Sounds and formed into a band. FIGUREl.- family at Kags Head, S.C., May 11, 1960, 1520 to 1530 EST. The figure was traced from a projected color trarlsparerlcy. Sotc vortices C, F, and C, and pendants B, D, and E;. Pendant B arid vortex C are paired as are E and F.

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pendant E; apparentlyremains, and pendant or vort,ex G still exists.

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CUkJLlJS FRACTUS 5-5 * NOT PART OF TORNADO

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FIGURE4.--Evolutio11 of torrlaclo-~~-vatcrspolItat Kngs Head, J~me27, 1960, 0715 to 0724 EST. The detached tip of stage 8 moved toward t,hc maintube and became part of the tornado in stage 10. alo~~g-thr,-tllhrmotion W:IS observed in stages 8, 9, and 11. The horizontal distance ~novcdby the system was 40' of arc.

cast while the curnulnscongestus tops moved from e:\st-nor.t,lIenst,. Thesc cumulus congest'us were not cspeci:1llyv mtlssive nor weret'hcir tips markedly high. Thcrc TWS no , thunder,or lightning, nor any agitation in thc bases of these clouds. This irlcident, clearly demon- strates the fact, that' t,hcsc sndlcr tornadoes can and do devclopin wcather that' is not'particularly threatening ttntl that no naturalwarning in thc Iorm of t'hunder 2. TORNADOES ON JUNE 27, 1960 neccssarily ttccompanies the vortex. Most of the lifetime of t'his tornadowas observed through On the morning of June 27 t'wo tornadoes were seen; binoculars and the steps of its development are illustrated thefirst wtw observed bet'ween 0715 and 0724 EST, :and in the sketches of figure 4. When firstseen it wasa wasunusual in that it moved lrorn t'he e:rst-nort~hcust. stubby, broad, and vertical pendant',as in sketch 1, which It occurred in a fairly compact band of cumulus congcstus never reached as much as one-fourth of the way to the which was oriented west-southwest to east~-northcast. The earth's surface. Tlle lower end gradually inclined toward surlace wind was northeast 8-10 m.p.h. and the cumulus the left (trailing portion) without, much lengt,hening until bases(appearing like cumulus fract'us) moved from the sket'cll 5, when the cloud t'ube st'arted to lengthen, bend,

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FIGURES.-Photographs made 3 miles from thetornado-water- spout of June 27, 1960, from 1100 to 1112 EST. Xote the long stinger and slendertaper in sect,iom A and B, and the final stubby pc~rldant insection C. Photos by Richard E. Jordan, Nags Head, S.C.

(9 and 9, which was rather rapid, may have been a growth or lengt~heningof the tube rather than :t movement. But thefact tlmt there w't~s a simultaneousdisappearing of the lower end of this tube, t'hough not, as fast RS the extension of the upper end (result,ingin n lengt,hening of thc tube) lcads me to think that there was an updraft' involvcd in the movmlent of the cloud. In sketch 8 the tl1rc:ttl-like lowercloud seemed to be dong the vortex :mis, but it joined the upper edge of the funnel base and irr1rnctli:ltely thefunnel lengthened (sketch 10) wit'll c-onsidernble width; it seemed as if the thread-like cloud had beer1 just the higher edge of a fairlythick inclined vortex. As mentionedabovc, there was a second tornadoon thismorning of' June 27. Tt was pllotographetl by Mr. R. E. Jordan who tookhis first, exposure close to 1100 EST, 9); minutes bcforc. I saw it. He WRS three nliles from itsneurtst' approach. His first photograph is reproducedin figure 58, whichshows A slantingfunnel taper,and narrow. In itslast' two minutes ithecatue with II very longand narrow stinger; no spray bushis gradually shorter and narrower,ant1 as it, findly disappe:md visible, buttmother obscrvc3r whowas in R directline it was almosthorizontal (sketch 14). Tllcfunnel was with the tornado's approach saw t~ sprav bush that broke lnostjly darkand opaque, but in sketch 7 it was light' up when t'he bush cwnc within a half-mile of the shore. gray in its lower part and showed to advantage against' This observer also saw a tube extending all the way from the dark background of cumulus fractus, which latter was the cloud base to thesea in the early st'ages, and it appeared notpart of the tornado. However, insketch 10 it w-ns that the tornadowas lifting water "right up into t'he sky.,' translucent. Mr. Jordan's second photograph, figure 5B, showsthe The few instances in whichan updraft could be observed upper funnel apparentlya little longer and the thin st'inger aremarked by short arrows. The apparent Inovenlent a lit't'le shorter t'han earlier. of the thread-like cloud tube toward the fume1 in sketches By 1109:30 EST, I saw this tornado-' andreal-

Unauthenticated | Downloaded 10/07/21 09:45 AM UTC (3) 1111 rm more thanin an ordinarycumulus base. The syst,em seemed to move quite rapidly during the 2% minutes that I observedit. Surface temperature and dew point were 79' ant1 66' F., respectively,and the wind gradually chnngctl from northeast to southeast during the morning. Scvemlpeople here have reported seeing two funnel cloudssoutheast of SagsHead at 0500 EST exist'ing sir,lultnnr.ousl\-. This makes a total of 4 known t,ornadoes or fullnels in this vicinitJ- in one morning. I got the impression t'hat there was an instability line with intermittentcumulus congest'us act'ivity along it, wihic*h driftedslowly northward during the morning. After thc 1100 EST dist'urbance,the line of cumulus congestus rrloved tothe north, and cunlulushumilis 1wc:mc 111ore predominmtwith 01113- isolatedcumulus c-ongestus later, still moving from the east,. The writerhopes that t'heseobservations will add to thc knowledge of tornadoes in general, and t'hat they can FIGUREG.-Three stages of the second tornado-Tvnterspout of June 27, 1960, between 1109:30 and 1112 EST, as seen by thc author bc used tl>Tt'llose who are setwching for theyet elusive from )4 mile away.Rather than wtrrowing with tjirne asother specific cause of t'hese phenomena. tornadoes have done, t,his tornado became thicker in its trunk portion. NOTE BY W. H. HOECKER-The importance of thebulbous pendantsncconlpanying the vortices described in figures 1-3 is etnplxtsizrd by the observation of a similar pendant which accom- ized thatit, was muchlarger than the earlier one. At p:tnied the earlier stage of the Dallas tornado of April 2, 1957, and which mas actuallp larger than the tornado at one t,ime Figure 2 this time I was about 1 mile fronl it ant1 could see it in shows t,hatthe pendant at Nags Head acconlpsnying the vortex detail. Its direction was from thc east in contrast to the D-1 was largerthan the vortex, but for the two other pairs the usual tornadomovement' from a westerlydirection. In vortex appeared larger, at least at the timeof the photographs from figure 6, are three sequences sketched as I saw them, ant1 which the sketches were made. these follow t'he first t)wo pictures taken by Mr. Jordan Theimportance of theobservations for June 27 involves the (fig. 5). unusual direction of movement of t,hese tornado- from the east and the fact that there was no natural warning to residents a The tornado hung from fairly large cumulus ard its in the form of lightning and thunder or associated wind. Also of tube was translucentwith a double udl beautifully importance is the shape evolution of the second tornado of June 27. formed. In sketch 2 (fig. 6), ut 111 1 EST, thetube was Contrary to a scheme of beinq short and wide in the early stage and very straight and it's slope exactly matched the slope of narrowing and lengthening at the late stage, as wa,s characteristic the cloud baseirlt'o which itextended. In sl&ch 3, at of Great Plains tornadoes investmigated by Hoecker[2,3], this tornado was long md slender when first observed and evolved into R short, EST as 1112 (nearly the same time the third picture by stubby pendant. Mr. Jordan (fig. 5C)) the tube suddenly grew wider antl 11uch is yet to be learned about the inception and evolution of suddenly dissolved as it was widening. Its width appeared thetornado and itis thought that these observations, by their uniform along its length at' this tirne, probably an effect of unusualnature, will pointto a generalizedconcept of tornado perspective as the lower end pointed 1110rc nearly toward formation and life history. me. At this stage the t'ube was a smooth gray color, but ACKNOWLEDGMENT it grew fainter as it widened, and maintained the appear- ance of translucence.Instead of disappearinginto a The writer is intlebt'ed to Mr. Walt'er H. Hoecker, Jr., level cloud base as it seems in figure 5C, it slanted up along of the 1T.S. Weather Bureau, Washingt'on, D.C., forhis the side of a ragged cun~ulus, merging slight'ly with it. excellent suggestions, and his extensive labor in compiling Muchof t'he lower tube AS I could see it does not' show in :Ind editing the figures antl matmerial in t'his note. the pict'ure (fig. 5C) because of an intervening cloud. REFERENCES The cumulus congestus cloud from which the tornado extended was part of a loosely assembled band or row of I. Frank B. Dinmiddie, " Waterspout-TornadoStructure and Hrhavior atSaps Head, N.C., August 12, 1952." Monthly cumulus congest'usoriented about northeast-southwest. Weather Review, vol. 87, No. 7, July 1959, pp. 239-250. These clouds were not very tall, but' 11ad hard edges at' the 2. \\-alter H. Hocxcker, Jr., "History and Measurement of the Two top. Some of the tops had excessively largepileus over 1l:tjor Scottsbluff Tornadoes of 27 June 1955," Bulletin oj the them and t'heir color was not whitebut dirt,y-looking; AntericanMeteorological Society, vol. 40 KO. 3, Mar. 1959, they were mostlikely not frozen. As withthe ctwlier pp. 117-133. 3.\\'alter H. Hoecker,Jr., "Dimensiorlal and Rotational Char- tornado on t'his day, there was no rain, thunder, or light- acteristics of thc Tornadoes and Their Cloud Systems," from ning with thislarger tornado-waterspout' and t'here was "The Tornadoes at Dallas, Texas, April 2, 1957," U.S. Weather no agitation in t,he cloud around the funnel or t'ube, no Bureau Research Paper No. 41, 1960, pp. 53-113.

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