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000 

WWUS20 KWNS 251756

SEL0

SPC WW 251756

NYZ000-PAZ000-VTZ000-260100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 650

NWS STORM PREDICTION CENTER NORMAN OK

155 PM EDT SAT AUG 25 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NEW YORK

       FAR NORTHERN PENNSYLVANIA

       VERMONT



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 155 PM UNTIL

900 PM 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 85

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

BINGHAMTON NEW YORK TO 40 MILES NORTH OF BURLINGTON VERMONT.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU0).



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...A VERY WARM AND MOIST AIR MASS IS ALREADY SUPPORTING

LARGE AREA OF MODERATE INSTABILITY ACROSS THIS REGION.  INCREASING

LOW LEVEL CONVERGENCE AND ASCENT AHEAD OF AN APPROACHING UPPER

SYSTEM WILL SUPPORT SCATTERED TO NUMEROUS THUNDERSTORMS MOVING

QUICKLY ENEWD DURING THE AFTERNOON AND EVENING.  SHEAR IS MORE THAN

ADEQUATE FOR SUPERCELLS AND ORGANIZED LINES OF STORMS.  ALTHOUGH A

TORNADO OR TWO CAN NOT BE RULED OUT...PRIMARY SEVERE THREATS ARE

EXPECTED TO BE DAMAGING WINDS AND ISOLATED LARGE HAIL.



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 500. MEAN STORM

MOTION VECTOR 26030.





...EVANS

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