MESOSCALE DISCUSSION 1674
   NWS STORM PREDICTION CENTER NORMAN OK
   1114 AM CDT THU JUL 21 2011
   
   AREAS AFFECTED...WRN AND SWRN ME AND NRN NH
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 211614Z - 211815Z
   
   THE SEVERE POTENTIAL MAY INCREASE THIS AFTERNOON FROM NRN VT AND NH
   INTO WRN ME. SUPERCELLS AND BOWING SEGMENTS WITH ISOLATED DAMAGING
   WIND...HAIL AND ISOLATED TORNADOES WILL BE POSSIBLE. POTENTIAL
   LIMITING FACTORS INCREASE THE UNCERTAINTY REGARDING EXTENT/TIMING OF
   THE SEVERE THREAT...AND ANY WW ISSUANCE WILL ULTIMATELY DEPEND ON
   CONVECTIVE/MESOSCALE TRENDS.
   
   WIDESPREAD CLOUDS AND SHALLOW CONVECTION HAS OVERSPREAD MUCH OF
   MAINE WITH BROKEN MID LEVEL CLOUDS EXTENDING SWWD INTO VT AND NH.
   THE CLOUDS AND PRECIPITATION ARE OCCURRING IN ASSOCIATION WITH
   ASCENT ATTENDING A COMPACT VORT MAX MOVING EWD THROUGH SRN
   QUEBEC...AND HAVE SIGNIFICANTLY LIMITED DESTABILIZATION ACROSS MUCH
   OF MAINE WHERE MLCAPE IS AOB 500 J/KG. SOUTH OF THE ZONE OF
   WIDESPREAD RAIN...MLCAPE IS APPROACHING 1000 J/KG OVER THE REMAINDER
   OF NEW ENGLAND. CLOUD TOPS HAVE BEEN COOLING AND AN INCREASE IN
   LIGHTNING HAS BEEN OBSERVED WITH STORMS OVER SERN QUEBEC...BUT THIS
   ACTIVITY MAY WEAKEN AS IT MOVES INTO THE LESS UNSTABLE ENVIRONMENT
   OVER MAINE. SLIGHTLY BETTER POTENTIAL FOR MORE ROBUST ACTIVITY
   EXISTS FARTHER SW ACROSS SWRN ME INTO VT AND NH WHERE STORMS MAY
   DEVELOP IN ASSOCIATION WITH CONFLUENCE BANDS AS THE BOUNDARY LAYER
   CONTINUES TO DESTABILIZE. EFFECTIVE SHEAR FROM 40-45 KT WILL SUPPORT
   ORGANIZED STORMS INCLUDING SUPERCELLS AND BOWING SEGMENTS.
   
   ..DIAL.. 07/21/2011
   
   
   ATTN...WFO...CAR...GYX...BTV...
   
   LAT...LON   45787029 46446986 46116872 45106902 44357057 44257235
               44747282 45147104 45787029