

000 

WWUS20 KWNS 151603

SEL8

SPC WW 151603

CTZ000-MAZ000-MEZ000-NHZ000-RIZ000-CWZ000-160000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 518

NWS STORM PREDICTION CENTER NORMAN OK

1200 PM EDT SUN JUL 15 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CONNECTICUT

       MASSACHUSETTS

       SOUTHWEST MAINE

       CENTRAL AND SOUTHERN NEW HAMPSHIRE

       RHODE ISLAND

       COASTAL WATERS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM NOON 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 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTHWEST

OF WINDSOR LOCKS CONNECTICUT TO 30 MILES SOUTH OF BANGOR MAINE.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 ARE EXPECTED TO INCREASE IN INTENSITY AND

COVERAGE NEXT 1-2 HOURS IN RESPONSE TO APPROACHING UPPER TROUGH AND

FURTHER HEATING/DESTABILIZATION OF AIR MASS WITHIN CLOUD-FREE

CORRIDOR.  MLCAPE IS EXPECTED TO REACH 1500 J/KG THIS

AFTERNOON...AND STRONG SWLY WINDS ALOFT ARE CONTRIBUTING TO DEEP

LAYER SHEAR OF 45-55 KT OVER THE REGION.  THESE FACTORS WILL SUPPORT

DEVELOPMENT OF STRONG/SEVERE STORMS WITH THE POSSIBILITY OF ISOLATED

SUPERCELLS.  PRIMARY THREATS WILL FOR DAMAGING WIND GUSTS AND

OCCASIONAL 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 450. MEAN STORM

MOTION VECTOR 24040.





...WEISS

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