

000 

WWUS20 KWNS 211813

SEL9

SPC WW 211813

NCZ000-VAZ000-WVZ000-220100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 629

NWS STORM PREDICTION CENTER NORMAN OK

215 PM EDT TUE AUG 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST NORTH CAROLINA

       WESTERN VIRGINIA

       A SMALL PART OF THE EASTERN WEST VIRGINIA PANHANDLE



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 215 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM STAUNTON VIRGINIA TO

15 MILES EAST SOUTHEAST OF HICKORY NORTH CAROLINA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU9).



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 DEVELOPING OVER THE MOUNTAINS AND

FOOTHILLS IN ADVANCE OF THE REMNANTS OF TS ERIN.  STRONG SURFACE

HEATING AND STEEP LOW-LEVEL LAPSE RATES WILL FAVOR DAMAGING

DOWNBURST WINDS AS CONVECTION ORGANIZES INTO SEVERAL SHORT LINE

SEGMENTS THROUGH THE AFTERNOON INTO NC/VA.



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 27030.





...THOMPSON

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