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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 482

NWS STORM PREDICTION CENTER NORMAN OK

350 PM EDT WED AUG 7 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EASTERN OHIO

  WESTERN PENNSYLVANIA PENNSYLVANIA

  NORTHERN WEST VIRGINIA PANHANDLE



* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 350 PM

  UNTIL 1000 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS TO 60 MPH POSSIBLE

  SEVERAL LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE

  A FEW TORNADOES POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTHWEST

OF WHEELING WEST VIRGINIA TO 30 MILES EAST NORTHEAST OF LATROBE

PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...STRONG/ISOLATED SEVERE STORM DEVELOPMENT IS ALREADY

UNDERWAY...AND COULD STILL INCREASE IN COVERAGE AND INTENSITY DURING

THE NEXT COUPLE OF HOURS AS IT DEVELOPS EAST SOUTHEASTWARD ALONG A

WARM FRONTAL TYPE ZONE...ACROSS THE UPPER OHIO VALLEY THROUGH THE

ALLEGHENY FRONT.  ALTHOUGH LOW-LEVEL SHEAR IS WEAK...DEEP LAYER

SHEAR IS SUFFICIENT FOR UPDRAFT ROTATION...AND IT IS NOT OUT OF THE

QUESTION THAT THE MOIST BOUNDARY LAYER COULD SUPPORT A BRIEF

TORNADO.  BUT MARGINALLY SEVERE HAIL MAY BE THE PRIMARY HAZARD...

BEFORE SOME STORM CONSOLIDATION AND UPSCALE GROWTH YIELDS AN

INCREASING RISK FOR DAMAGING WIND GUSTS LATE THIS AFTERNOON INTO

EARLY EVENING.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 29030.





...KERR

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