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WWUS20 KWNS 250129

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INZ000-KYZ000-NYZ000-OHZ000-PAZ000-LEZ000-LOZ000-250900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 804

NWS STORM PREDICTION CENTER NORMAN OK

920 PM EDT WED AUG 24 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EAST CENTRAL AND SOUTHEAST INDIANA

       FAR NORTHERN KENTUCKY

       WESTERN NEW YORK

       WESTERN...CENTRAL...AND NORTHERN OHIO

       NORTHWEST PENNSYLVANIA

       LAKE ERIE

       LAKE ONTARIO



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 920 PM

UNTIL 500 AM EDT.



HAIL TO 1.5 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 90

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES EAST

SOUTHEAST OF BLOOMINGTON INDIANA TO 40 MILES NORTHWEST OF BUFFALO

NEW YORK.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 802...WW 803...



DISCUSSION...BROKEN BANDS OF SUPERCELLS AND STRONG MULTICELLS NOW

OVER LWR MI/SW ONT/NRN IND EXPECTED TO CONTINUE GENERALLY E/SE

ACROSS THE NW HALF OF OHIO AND INTO NW PA/WRN NY THROUGH EARLY

THU...AHEAD OF AMPLIFYING SHORTWAVE TROUGH NOW NEARING LK MI.  40-50

KT LARGELY UNIDIRECTIONAL WSWLY 700-500 MB FLOW WILL BE FAVORABLE

FOR LEWPS/ EMBEDDED SUPERCELLS WITH HIGH WIND/SVR HAIL AND A BRIEF

TORNADO OR TWO.  A NON-ZERO THREAT ALSO WILL EXIST FOR LONGER-LIVED

TORNADOES...PARTICULARLY OVER NRN OH AND FAR NW PA...WHERE LOW LVL

WINDS MAY REMAIN SLIGHTLY BACKED INVOF DIFFUSE NNE/SSW WARM

FRONT/LOW LVL MOISTURE GRADIENT.  ATTM...EXISTING QUASI-LINEAR STORM

MODE AND INCREASING BOUNDARY LAYER CINH SUGGEST THAT THE THREAT FOR

LONGER-LIVED TORNADOES IS LOW ENOUGH TO NOT WARRANT A TORNADO WATCH.

 HOWEVER...SHOULD MORE DISCRETE STORMS APPEAR OVER WRN LK ERIE...NE

IND...OR NW OH LATER THIS EVE...PARTS OF OH AND NW PA MAY REQUIRE

UPGRADE TO TORNADO.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

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

MOTION VECTOR 29040.





...CORFIDI

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