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WWUS20 KWNS 090756

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NYZ000-OHZ000-PAZ000-LEZ000-LOZ000-091500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 449

NWS STORM PREDICTION CENTER NORMAN OK

355 AM EDT THU JUN 9 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF WESTERN NEW YORK

       LARGE PART OF NORTHERN OHIO

       PARTS OF NORTH AND WEST PENNSYLVANIA

       LAKE ERIE

       LAKE ONTARIO



EFFECTIVE THIS THURSDAY MORNING FROM 355 AM UNTIL 1100 AM EDT.



HAIL TO 2 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 NORTH AND SOUTH OF A LINE FROM 15 MILES SOUTH

SOUTHWEST OF FINDLAY OHIO TO 30 MILES NORTH NORTHEAST OF ITHACA

NEW YORK.  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.



DISCUSSION...LARGE COLD POOL CONTINUING EWD ACROSS SWRN ONTARIO INTO

NRN OH WHICH WILL CONTINUE TO GENERATE STRONG/SEVERE THUNDERSTORMS

ON LEADING EDGE. WITH A STILL UNSTABLE AIR MASS ACROSS THE WATCH

AREA COUPLED WITH STEEP MID LEVEL LAPSE RATES...DAMAGING WINDS WILL

BE A THREAT WITH THE PASSAGE OF THE COLD POOL ALONG WITH LARGE HAIL

IN STRONGEST THUNDERSTORM CORES.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 28035.





...HALES

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