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WWUS20 KWNS 121850

SEL2

SPC WW 121850

DCZ000-MDZ000-VAZ000-CWZ000-130100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 602

NWS STORM PREDICTION CENTER NORMAN OK

250 PM EDT THU AUG 12 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       PARTS OF CENTRAL MARYLAND

       PARTS OF NORTHERN VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 250 PM UNTIL

900 PM EDT.



HAIL TO 1 INCH 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 65

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

NORTHWEST OF WASHINGTON DISTRICT OF COLUM TO 50 MILES EAST

SOUTHEAST OF CHARLOTTESVILLE VIRGINIA.  FOR A COMPLETE DEPICTION

OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS

WOU2).



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 601...



DISCUSSION...THUNDERSTORMS HAVE REDEVELOPED ACROSS NRN VA AHEAD OF

VORT MAX/TROUGH MOVING ESEWD ACROSS PA. WITH AIR MASS AGAIN VERY

MOIST/MDTLY UNSTABLE...THUNDERSTORMS WITH PRIMARILY A WIND DAMAGE

THREAT WILL MOVE SEWD ACROSS THE WATCH AREA.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

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

VECTOR 32025.





...HALES

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