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WWUS20 KWNS 021919

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NYZ000-PAZ000-LOZ000-030200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 510

NWS STORM PREDICTION CENTER NORMAN OK

320 PM EDT MON SEP 2 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  A LARGE PORTION OF NEW YORK

  MUCH OF THE NORTHERN HALF OF PENNSYLVANIA

  LAKE ONTARIO



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 320 PM UNTIL

  1000 PM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 65 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES EAST AND WEST OF A LINE FROM 90 MILES EAST

NORTHEAST OF WATERTOWN NEW YORK TO 20 MILES SOUTHEAST OF DUBOIS

PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 CONTINUE TO GRADUALLY INCREASE/ORGANIZE

THIS AFTERNOON IN A DESTABILIZING ENVIRONMENT AHEAD OF AN ADVANCING

SURFACE COLD FRONT AND ASSOCIATED UPPER LOW/TROUGH.

WLY DEEP-LAYER WIND FIELD CONTINUES TO INCREASE WITH TIME ACROSS

THIS REGION AS STRONGER FLOW ON THE SOUTH SIDE OF THE UPPER LOW

SPREADS EASTWARD...AND THIS COMBINATION OF INCREASING CAPE AND SHEAR

SHOULD SUPPORT BANDS OF STRONG/SEVERE STORMS THROUGH THE AFTERNOON

AND EARLY EVENING.  WHILE LARGE HAIL WILL BE A PRIMARY SEVERE

RISK...THREAT FOR LOCALLY DAMAGING WINDS IS LIKELY TO INCREASE IN

THE NEXT 1-2 HOURS AS STORMS LOCALLY GROW UPSCALE INTO SMALL-SCALE

LINES.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 55

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

MOTION VECTOR 28035.





...GOSS

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