

108 

WWUS20 KWNS 121628

SEL0

SPC WW 121628

GAZ000-NCZ000-SCZ000-VAZ000-CWZ000-130100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 700

NWS STORM PREDICTION CENTER NORMAN OK

1225 PM EDT WED AUG 12 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST GEORGIA

       EASTERN NORTH CAROLINA

       EASTERN SOUTH CAROLINA

       SOUTHEAST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 1225 PM UNTIL

900 PM EDT.



HAIL TO 2 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 60

STATUTE MILES EITHER SIDE OF A LINE FROM 10 MILES EAST SOUTHEAST

OF NORFOLK VIRGINIA TO 25 MILES WEST SOUTHWEST OF SAVANNAH

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.



DISCUSSION...THUNDERSTORMS ARE INCREASING OVER ERN SC...AND

ADDITIONAL STORMS ARE LIKELY TO DEVELOP NEAR THE FRONTAL BOUNDARY

EXTENDING FROM SERN VA INTO SRN GA.  AIR MASS OVER THIS REGION IS

VERY MOIST WITH SURFACE DEW POINTS IN THE LOW/MID 70S...AND WITH

TEMPERATURES WARMING INTO THE 80S IS RESULTING IN MLCAPE OF

1500-2500 J/KG.  WSWLY FLOW ALOFT INCREASES TO 30-40 KT ABOVE 3 KM

OVER NC AND VA...AND TO 25-30 KT OVER SC...WHICH WILL PROMOTE

DEVELOPMENT OF ORGANIZED STORMS INCLUDING ISOLATED SUPERCELLS AND

SHORT BOWING LINE SEGMENTS. STRONGER STORMS WILL BE CAPABLE OF

PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 26025.





...WEISS

