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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 629

NWS STORM PREDICTION CENTER NORMAN OK

325 PM EDT FRI SEP 7 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST OHIO

       NORTHWEST PENNSYLVANIA

       LAKE ERIE



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 325 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 40

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHEAST

OF FRANKLIN PENNSYLVANIA TO 10 MILES SOUTHWEST OF MANSFIELD OHIO.

 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 628...



DISCUSSION...A BROKEN BAND OF STORMS WILL CONTINUE TO SPREAD EWD

INTO NE OH THIS AFTERNOON/EVENING...WITH ADDITIONAL DEVELOPMENT

POSSIBLE INTO NW PA.  THE COMBINATION OF MODERATE INSTABILITY AND A

GRADUAL INCREASE IN VERTICAL SHEAR WILL CONTINUE TO SUPPORT A RISK

OF MAINLY ORGANIZED MULTICELL CLUSTERS/LINE SEGMENTS CAPABLE OF

PRODUCING DAMAGING WINDS AND LARGE HAIL.



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 27030.





...THOMPSON

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