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833 

WWUS20 KWNS 241709

SEL7

SPC WW 241709

CTZ000-MAZ000-MEZ000-NHZ000-RIZ000-CWZ000-250000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 407

NWS STORM PREDICTION CENTER NORMAN OK

105 PM EDT THU JUN 24 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN CONNECTICUT

       MUCH OF MASSACHUSETTS

       SOUTHERN AND WESTERN MAINE

       NEW HAMPSHIRE

       RHODE ISLAND

       COASTAL WATERS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 105 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 100

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHEAST OF

MOUNT WASHINGTON NEW HAMPSHIRE TO 25 MILES SOUTH SOUTHWEST OF NEW

BEDFORD MASSACHUSETTS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 404...WW 405...WW 406...



DISCUSSION...FRONTAL AND PRE-FRONTAL TSTMS NOW INCREASING IN FAST

WLY FLOW ON S SIDE OF ST LAWRENCE VLY UPR VORT SHOULD CONTINUE E

INTO WW AREA LATER THIS AFTN.  40-50 KT DEEP WLY SHEAR AND

TERRAIN-GENERATED BOUNDARIES SHOULD SUPPORT A FEW SUSTAINED

STORMS/SUPERCELLS.  THESE COULD YIELD A FEW SWATHS OF DMGG

WIND/MARGINALLY SVR HAIL.  A CONDITIONAL RISK ALSO WILL EXIST FOR A

TORNADO OR TWO IN AREAS WHERE TERRAIN INFLUENCES/LOW LVL BOUNDARY

SEGMENTS KEEP LOW LVL FLOW SLIGHTLY BACKED...MOST LIKELY IN MAINE.



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 27045.





...CORFIDI

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