

578 

WWUS20 KWNS 141841

SEL0

SPC WW 141841

GAZ000-SCZ000-CWZ000-150100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 780

NWS STORM PREDICTION CENTER NORMAN OK

240 PM EDT SUN AUG 14 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME EAST CENTRAL GEORGIA

       CENTRAL AND EASTERN SOUTH CAROLINA

       COASTAL WATERS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 240 PM UNTIL 900

PM EDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH OF

FLORENCE SOUTH CAROLINA TO 35 MILES SOUTHEAST OF VIDALIA GEORGIA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 779...



DISCUSSION...THUNDERSTORMS WILL CONTINUE TO INCREASE IN

COVERAGE/INTENSITY THIS AFTERNOON ALONG A DIFFERENTIAL HEATING ZONE

FROM EARLIER CLOUDS...AND ALONG A DIFFUSE SURFACE TROUGH NEAR THE

SAVANNAH RIVER.  STORM COVERAGE WILL BE FURTHER AUGMENTED BY WEAK

ASCENT DOWNSTREAM FROM A MIDLEVEL TROUGH ROTATING SEWD OVER THE SRN

APPALACHIANS.  GIVEN SOME INCREASE IN MIDLEVEL FLOW...MODEST

MIDLEVEL LAPSE RATES...AND MLCAPE IN EXCESS OF 1500 J/KG...A FEW OF

THE STORMS WILL BE CAPABLE OF PRODUCING DAMAGING DOWNBURSTS THIS

AFTERNOON/EVENING.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 28025.





...THOMPSON

