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025 

WWUS20 KWNS 091806

SEL6

SPC WW 091806

DCZ000-KYZ000-MDZ000-OHZ000-VAZ000-WVZ000-CWZ000-100100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 356

NWS STORM PREDICTION CENTER NORMAN OK

205 PM EDT TUE JUN 9 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       DISTRICT OF COLUMBIA

       EXTREME NORTHEAST KENTUCKY

       MUCH OF MARYLAND

       SOUTHEAST OHIO

       NORTHERN VIRGINIA

       NORTHERN AND CENTRAL WEST VIRGINIA

       COASTAL WATERS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 205 PM UNTIL

900 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 ATHENS OHIO TO 25 MILES SOUTHEAST OF BALTIMORE

MARYLAND.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 354...WW 355...



DISCUSSION...SCATTERED THUNDERSTORMS WILL PERSIST THROUGH THE

AFTERNOON ALONG AND SE OF A SLOW-MOVING COLD FRONT ACROSS SE OH AND

CENTRAL PA.  THOUGH DEEP LAYER FLOW AND VERTICAL SHEAR IS WEAKER

THAN AREAS FARTHER N...MODERATE TO STRONG INSTABILITY WITH DAYTIME

HEATING AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT A THREAT FOR

DAMAGING DOWNBURST WINDS AND LARGE HAIL WITH MULTICELL CLUSTERS.

ACTIVITY IS EXPECTED TO SPREAD SLOWLY SEWD THROUGH THE AFTERNOON

ACROSS WV AND NRN VA.



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 29020.





...THOMPSON

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