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000 

WWUS20 KWNS 101622

SEL4

SPC WW 101622

NYZ000-PAZ000-VTZ000-110000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 264

NWS STORM PREDICTION CENTER NORMAN OK

1220 PM EDT THU MAY 10 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND EASTERN NEW YORK

       CENTRAL AND EASTERN PENNSYLVANIA

       WESTERN VERMONT



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1220 PM UNTIL

800 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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF

BURLINGTON VERMONT TO 25 MILES WEST OF HARRISBURG PENNSYLVANIA.

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.



DISCUSSION...THUNDERSTORMS ARE EXPECTED TO INTENSIFY ALONG COLD

FRONT AND OUTFLOW BOUNDARY MOVING EWD THROUGH NY AND PA AS WELL AS

IN WARM SECTOR. THE ATMOSPHERE WILL BECOME MODERATELY UNSTABLE WITH

MLCAPE TO 1500 J/KG AND STEEP MID LEVEL LAPSE RATES. VERTICAL SHEAR

PROFILES WILL SUPPORT MULTICELLS AND LINES CAPABLE OF PRODUCING

ISOLATED DAMAGING WIND AND HAIL THROUGH EARLY EVENING.



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 24020.





...DIAL/HALES

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