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WWUS20 KWNS 091656

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 451

NWS STORM PREDICTION CENTER NORMAN OK

1255 PM EDT THU JUN 9 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR EASTERN KENTUCKY

       WESTERN MARYLAND

       SOUTHEASTERN OHIO

       MUCH OF PENNSYLVANIA

       WESTERN VIRGINIA

       MUCH OF WEST VIRGINIA



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL

800 PM EDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH

SOUTHEAST OF WILLIAMSPORT PENNSYLVANIA TO 30 MILES WEST NORTHWEST

OF CHARLESTON WEST VIRGINIA.  FOR A COMPLETE DEPICTION OF THE

WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 450...



DISCUSSION...STORMS ARE EXPECTED TO DEVELOP ALONG APPROACHING COLD

FRONT...OUTFLOW BOUNDARIES AND OVER THE HIGHER TERRAIN DURING THE

NEXT FEW HOURS. A VERY UNSTABLE AIR MASS ALONG WITH DEEP LAYER SHEAR

AT 30 KT WILL BE FAVORABLE FOR SEVERE MULTICELL STORMS. WHILE HAIL

LIKELY WILL BE THE PRIMARY THREAT ONCE STORMS DEVELOP ...THE STORMS

ARE EXPECTED TO ORGANIZE INTO LINES LATER THIS AFTERNOON...WITH WIND

DAMAGE BECOMING THE GREATER THREAT.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 27025.





...IMY

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