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WWUS20 KWNS 051643

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NYZ000-LEZ000-LOZ000-052300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 563

NWS STORM PREDICTION CENTER NORMAN OK

1245 PM EDT SUN AUG 5 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NEW YORK

       LAKE ERIE

       LAKE ONTARIO



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1245 PM UNTIL

700 PM EDT.



HAIL TO 1 INCH 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTH

NORTHEAST OF UTICA NEW YORK TO 25 MILES NORTH NORTHWEST OF

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

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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...CONVECTIVE CLUSTER OVER ERN LAKE ERIE WILL MOVE NEWD

ACROSS WRN NY THROUGH THE AFTERNOON.  A SMALL AREA OF CLOUD BREAKS A

FEW COUNTIES AHEAD OF THIS CONVECTION WILL MAINTAIN MODEST

SURFACE-BASED INSTABILITY...IN AN ENVIRONMENT WITH 35-45 KT

LOW-MIDLEVEL SWLY FLOW ON THE SE FRINGE OF AN EJECTING SHORTWAVE

TROUGH.  DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

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

VECTOR 24035.





...THOMPSON

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