

867 

WWUS20 KWNS 162157

SEL6

SPC WW 162157

GAZ000-NCZ000-SCZ000-TNZ000-VAZ000-170500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 436

NWS STORM PREDICTION CENTER NORMAN OK

555 PM EDT TUE JUN 16 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME NORTHEAST GEORGIA

       WESTERN NORTH CAROLINA

       UPSTATE SOUTH CAROLINA

       EASTERN TENNESSEE

       WESTERN VIRGINIA



EFFECTIVE THIS TUESDAY AFTERNOON AND WEDNESDAY MORNING FROM 555

PM UNTIL 100 AM 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 80

STATUTE MILES EITHER SIDE OF A LINE FROM 15 MILES SOUTH SOUTHWEST

OF CHARLOTTE NORTH CAROLINA TO 55 MILES NORTH NORTHEAST OF

KNOXVILLE TENNESSEE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 433...WW 434...WW 435...



DISCUSSION...WELL-DEFINED BOW ECHO WITH DAMAGING WINDS IS MOVING EWD

ALONG THE SE KY/NE TN BORDER AT ABOUT 45 KT.  THIS SYSTEM MAY TEND

TO PROPAGATE MORE ESEWD OVER THE NEXT FEW HOURS AS IT ENCOUNTERS AN

INSTABILITY GRADIENT WITH COOLER/MORE STABLE AIR FARTHER TO THE E IN

NC/VA.  MEANWHILE...MORE ISOLATED STORMS ARE ONGOING ACROSS SC ALONG

THE SAME INSTABILITY GRADIENT.  VERTICAL SHEAR AND INSTABILITY ARE

AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS ACROSS SC...WITH LARGE

HAIL THE MAIN THREAT.



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 500. MEAN STORM

MOTION VECTOR 28040.





...THOMPSON

