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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 834

NWS STORM PREDICTION CENTER NORMAN OK

1255 PM EDT SUN SEP 4 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND NORTHERN MAINE

       NORTHERN AND CENTRAL NEW HAMPSHIRE



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1255 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH

NORTHWEST OF CARIBOU MAINE TO 15 MILES SOUTHEAST OF MOUNT

WASHINGTON 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 832...WW 833...



DISCUSSION...A WEAK LEAD MID-LEVEL IMPULSE EJECTING NEWD WELL-AHEAD

OF PARENT TROUGH OVER THE GREAT LAKES WILL CONTINUE INTO NRN NEW

ENGLAND THIS AFTN/EARLY EVE.  ASSOCIATED BAND OF TSTMS HAS

INTENSIFIED AS AIR MASS BECOMES MODESTLY UNSTABLE /MLCAPES TO 2000 J

PER KG/.  REGION RESIDES ALONG SRN FRINGES OF 35-40 KT DEEP LAYER

SHEAR THAT WILL BE CONDUCIVE FOR BRIEF SUPERCELLS AND/OR BOWING LINE

SEGMENTS WITH DMGG WIND GUSTS AND HAIL.



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 400. MEAN STORM

MOTION VECTOR 25035.





...RACY

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