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000 

WWUS20 KWNS 272043

SEL1

SPC WW 272043

DCZ000-MDZ000-VAZ000-WVZ000-CWZ000-280200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 301

NWS STORM PREDICTION CENTER NORMAN OK

445 PM EDT SUN MAY 27 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       CENTRAL MARYLAND

       NORTHERN VIRGINIA

       EASTERN WEST VIRGINIA PANHANDLE

       COASTAL WATERS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 445 PM UNTIL

1000 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH

SOUTHWEST OF MARTINSBURG WEST VIRGINIA TO 25 MILES EAST SOUTHEAST

OF BALTIMORE MARYLAND.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 300...



DISCUSSION...CLUSTER OF STRONG THUNDERSTORMS OVER NORTHERN VA MAY

PERSIST FOR SEVERAL HOURS AND TRACK SLOWLY EASTWARD ACROSS

DC/BALTIMORE METRO AREAS.  TEMPERATURES NEAR 90F HAVE RESULTED IN

STEEP LOW LEVEL LAPSE RATES AND MUCAPE VALUES OVER 2500 J/KG.

ISOLATED CELLS IN THIS AREA MAY POSE A THREAT OF DAMAGING WINDS AND

HAIL.



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 27025.





...HART

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