

242 

WWUS20 KWNS 210237

SEL4

SPC WW 210237

NYZ000-LOZ000-210500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 724

NWS STORM PREDICTION CENTER NORMAN OK

1040 PM EDT THU AUG 20 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL NEW YORK

       LAKE ONTARIO



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1040 PM

UNTIL 100 AM EDT.



HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 60

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 35

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES WEST

SOUTHWEST OF ELMIRA NEW YORK TO 30 MILES NORTH NORTHWEST OF

WATERTOWN 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 722...WW 723...



DISCUSSION...QLCS WITH EMBEDDED LEWPS/SMALL BOWING SEGMENTS WILL

CONTINUE GENERALLY ENE...WITH AN ISOLD STORM OR TWO AHEAD OF LINE.

NOCTURNAL COOLING SHOULD RESULT IN GRADUAL WEAKENING OF CONVECTION

LATER THIS EVENING.  BUT GIVEN MOIST LOW LVL ENVIRONMENT AND

STRENGTH OF DEEP WIND FIELD...POTENTIAL FOR ISOLD SVR LIKELY WILL

LINGER FOR A COUPLE MORE HOURS.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50 KNOTS.

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

VECTOR 23030.





...CORFIDI

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