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WWUS20 KWNS 021521

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MEZ000-NHZ000-CWZ000-022300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 718

NWS STORM PREDICTION CENTER NORMAN OK

1120 AM EDT TUE AUG 2 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST MAINE

       EASTERN NEW HAMPSHIRE

       COASTAL WATERS



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1120 AM UNTIL 700

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 35

STATUTE MILES EITHER SIDE OF A LINE FROM 25 MILES SOUTH OF

LACONIA NEW HAMPSHIRE TO 35 MILES EAST NORTHEAST OF AUGUSTA

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.



OTHER WATCH INFORMATION...CONTINUE...WW 717...



DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON IN ADVANCE OF MIDLEVEL VORTICITY MAXIMUM

TRANSLATING SEWD ACROSS THE REGION.  THE COMBINATION OF COOLING

MIDLEVEL TEMPERATURES AND DAYTIME HEATING ARE EXPECTED TO YIELD

MODERATE AFTERNOON INSTABILITY WITH MLCAPE OF 1000-1500 J/KG.

VERTICAL SHEAR WILL REMAIN SOMEWHAT MARGINAL FOR STORM

ORGANIZATION...BUT SEVERE HAIL WILL BE POSSIBLE WITH THE MOST

INTENSE UPDRAFT CORES.



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 33020.





...MEAD

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