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989 

WWUS20 KWNS 242246

SEL9

SPC WW 242246

NCZ000-VAZ000-250400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 109

NWS STORM PREDICTION CENTER NORMAN OK

645 PM EDT SAT MAR 24 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHERN NORTH CAROLINA

       CENTRAL AND SOUTHERN VIRGINIA



EFFECTIVE THIS SATURDAY NIGHT FROM 645 PM UNTIL MIDNIGHT EDT.



TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE

MILES EITHER SIDE OF A LINE FROM 20 MILES NORTH NORTHEAST OF

RICHMOND VIRGINIA TO 25 MILES WEST NORTHWEST OF DANVILLE

VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 104...WW 105...WW

106...WW 107...WW 108...



DISCUSSION...LONG-LIVED TSTM/CYCLIC SUPERCELL NOW NEAR LYNCHBURG VA

EXPECTED TO CONTINUE NE TO ENE AT ABOUT 20-25 KTS.  STORM APPEARS TO

HAVE BEEN AIDED BY SHALLOW WSW-ENE ORIENTED BOUNDARY THAT BECOMES

MORE DIFFUSE WITH EWD EXTENT ACROSS S CNTRL VA.  STRENGTH OF STORM

AND REASONABLY UNSTABLE/MOIST ESELY LOW LVL FLOW AHEAD OF IT SUGGEST

THAT IT MAY PERSIST FOR SOME TIME LATER THIS EVE...POSING A THREAT

FOR SVR HAIL AND POSSIBLY A TORNADO.  FARTHER S...STORMS ARE

EXPECTED TO INCREASE ALONG NNE-SSW CONFLUENCE AXIS EXTENDING FROM

NEAR LYNCHBURG INTO PIEDMONT NC.  SUFFICIENT DEEP SHEAR AND FORCING

FOR ASCENT APPEAR PRESENT TO SUPPORT A RISK FOR INTERMITTENT

SUPERCELL STRUCTURES THAT WOULD BE CAPABLE OF SVR HAIL...LOCALLY

DMGG WIND...AND PERHAPS ONE OR TWO TORNADOES THROUGH MID TO LATE

EVE.



AVIATION...TORNADOES AND 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

400. MEAN STORM MOTION VECTOR 24020.





...CORFIDI

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