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917 

WWUS20 KWNS 240031

SEL9

SPC WW 240031

KYZ000-OHZ000-PAZ000-WVZ000-LEZ000-240600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 349

NWS STORM PREDICTION CENTER NORMAN OK

830 PM EDT MON MAY 23 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME NORTHEAST KENTUCKY

       EASTERN OHIO

       WESTERN PENNSYLVANIA

       WEST CENTRAL AND NORTHWEST WEST VIRGINIA

       LAKE ERIE



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 830 PM UNTIL

200 AM 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 60

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

NORTHWEST OF BRADFORD PENNSYLVANIA TO 60 MILES SOUTHWEST OF

HUNTINGTON WEST VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 342...WW 344...WW

345...WW 346...WW 347...WW 348...



DISCUSSION...WELL-FORMED QLCS OVER OH/NRN KY WILL CONTINUE EWD

TOWARD THE UPPER OH VALLEY INTO THE EARLY OVERNIGHT HOURS.  THOUGH

THE BOUNDARY LAYER WILL GRADUALLY COOL/STABILIZE AHEAD OF THE

STORMS...INSTABILITY AND LOW-MIDLEVEL VERTICAL SHEAR SHOULD REMAIN

SUFFICIENT FOR ORGANIZED STORMS WITH A DAMAGING WIND AND ISOLATED

HAIL RISK.  OTHER MORE ISOLATED CELLS MAY PERSIST FOR ANOTHER COUPLE

OF HOURS ACROSS NE OH/NW PA IN THE WARM ADVECTION REGIME.



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 27040.





...THOMPSON

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