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WWUS20 KWNS 172337

SEL4

SPC WW 172337

NHZ000-NYZ000-VTZ000-180500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 654

NWS STORM PREDICTION CENTER NORMAN OK

740 PM EDT SUN JUL 17 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN NEW HAMPSHIRE

       UPSTATE NEW YORK

       NORTHERN VERMONT



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 740 PM UNTIL

100 AM 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 40

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH

SOUTHWEST OF MASSENA NEW YORK TO 15 MILES SOUTH SOUTHEAST OF

BERLIN NEW HAMPSHIRE.  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 652...WW 653...



DISCUSSION...A FAST MOVING BOW ECHO ALONG THE ONTARIO/QUEBEC BORDER

WILL TRACK RAPIDLY SOUTHEASTWARD ACROSS THE WATCH AREA DURING THE

NEXT FEW HOURS.  STRONG WINDS ALOFT AND STEEP LOW LEVEL LAPSE RATES

WILL PROMOTE A RISK OF DAMAGING WINDS ALONG THE LEADING EDGE OF THE

BOW.  INSTABILITY WILL BEGIN TO WEAKEN AFTER SUNSET...WHICH MAY

LIMIT THE SOUTH AND SOUTHEASTWARD EXTENT OF THE SEVERE THREAT.



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 30040.





...HART

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