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000 

WWUS20 KWNS 221717

SEL4

SPC WW 221717

DCZ000-MDZ000-NCZ000-VAZ000-WVZ000-CWZ000-230000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 594

NWS STORM PREDICTION CENTER NORMAN OK

115 PM EDT SUN JUN 22 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       MOST OF MARYLAND

       NORTHERN NORTH CAROLINA

       WESTERN AND NORTHERN VIRGINIA

       EASTERN WEST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 115 PM UNTIL 800

PM 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTHWEST OF

GREENSBORO NORTH CAROLINA TO 30 MILES NORTHEAST OF MARTINSBURG

WEST VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 593...



DISCUSSION...TSTMS SHOULD CONTINUE TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON E OF THE BLUE RIDGE WITHIN MODERATELY

UNSTABLE AIR MASS WITH SBCAPES OF 1500-2500 J/KG.  SOME

STRENGTHENING OF VERTICAL SHEAR IS FORECAST WITH KINEMATIC

ENVIRONMENT BECOMING SUPPORTIVE OF ORGANIZED STORM CLUSTERS AND/OR

LINE SEGMENTS CAPABLE OF DAMAGING WINDS AND LARGE HAIL.



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 25025.





...MEAD/THOMPSON

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