

120 

WWUS20 KWNS 041845

SEL5

SPC WW 041845

NYZ000-PAZ000-VTZ000-050300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 835

NWS STORM PREDICTION CENTER NORMAN OK

245 PM EDT SUN SEP 4 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND PARTS OF EASTERN NEW YORK

       NORTHEAST PENNSYLVANIA

       VERMONT



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 245 PM UNTIL

1100 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF

BURLINGTON VERMONT TO 15 MILES SOUTH SOUTHWEST OF WILLIAMSPORT

PENNSYLVANIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 832...WW 833...WW 834...



DISCUSSION...LARGE-SCALE ASCENT FOR FORCING WILL GRADUALLY INCREASE

LATE THIS AFTN AND EVE AS PRIMARY UPR TROUGH CONTINUES TO SPREAD

ACROSS THE GRTLKS REGION.  INCREASING CONVERGENCE ALONG A

PRE-FRONTAL TROUGH WILL BE FAVORABLE FOR BANDS/CLUSTERS OF TSTMS TO

FORM FROM CNTRL/ERN NY SWWD INTO PARTS OF NRN PA WITH SUBSEQUENT

MOVEMENT ENE PARTS OF NRN NEW ENGLAND THIS EVENING.  INCREASING

WSWLY MID-LVL FLOW WILL BOOST DEEP LAYER SHEAR INTO THE 35-40 KT

RANGE AND BE FAVORABLE FOR ISOLD SUPERCELLS...PARTICULARLY N OF THE

PA/NY STATE LINE.  HOWEVER...BOW ECHO CONVECTIVE MODE IS MORE LIKELY

WITH ATTENDANT DMGG WIND GUSTS/LARGE HAIL RISKS.



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 25035.





...RACY

