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000 

WWUS20 KWNS 082135

SEL2

SPC WW 082135

DCZ000-MDZ000-PAZ000-VAZ000-WVZ000-CWZ000-090300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 372

NWS STORM PREDICTION CENTER NORMAN OK

535 PM EDT FRI JUN 8 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       WESTERN...CENTRAL AND SOUTHERN MARYLAND

       SOUTH CENTRAL PENNSYLVANIA

       NORTHERN AND CENTRAL VIRGINIA

       EASTERN WEST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 535 PM UNTIL

1100 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 80

STATUTE MILES EITHER SIDE OF A LINE FROM 50 MILES EAST OF

HARRISBURG PENNSYLVANIA TO 10 MILES SOUTH SOUTHWEST OF ELKINS

WEST 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 369...WW 370...WW 371...



DISCUSSION...TSTMS EXPECTED TO DEVELOP EWD INTO WW AREA AS UPR

DIFFLUENCE/INCREASED WLY FLOW ON SRN FRINGE OF ERN GRT LKS TROUGH

ENHANCE UVV/SHEAR OVER REGION.  WHILE MID LEVEL LAPSE RATES WILL

REMAIN WEAK...LOW LEVEL LAPSE RATES HAVE BEEN STEEPENED BY STRONG

SFC HEATING.  COUPLED WITH EVENTUAL ARRIVAL OF COLD-POOL DRIVEN SQLN

NOW CROSSING WV...SETUP COULD SUPPORT SCTD INSTANCES OF HIGH

WIND/HAIL INTO MID EVENING.



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.





...CORFIDI

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