MESOSCALE DISCUSSION 1062
   NWS STORM PREDICTION CENTER NORMAN OK
   0843 PM CDT WED JUN 01 2011
   
   AREAS AFFECTED...PORTIONS OF MAINE...NH...MA...CT...RI
   
   CONCERNING...TORNADO WATCH 416...
   
   VALID 020143Z - 020315Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 416 CONTINUES.
   
   THE SEVERE THREAT ACROSS WW416 IS CONFINED TO TWO SPATIAL CORRIDORS.
   
   THE FIRST CORRIDOR IS ACROSS PORTIONS OF ERN MA AND NERN CT
   EXTENDING TO THE ATLANTIC COAST. RELATIVELY MORE DISCRETE CONVECTIVE
   STRUCTURES HAVE EVOLVED INTO A QLCS EXTENDING FROM 5 NNW BOS TO 25
   WNW PVD IN RESPONSE TO EARLIER MERGING OF COLD POOLS. A SHORT-TERM
   THREAT FOR DMGG WINDS AND LARGE HAIL WILL CONTINUE...AS WELL AS
   POSSIBLY A TORNADO GIVEN A 0-1 KM SRH VALUE OF 270 M2/S2 OBSERVED ON
   THE 00Z CHATHAM MA SOUNDING. HOWEVER...AS THIS ACTIVITY CROSSES A
   STATIONARY BOUNDARY EXTENDING NEAR AND JUST WEST OF THE ATLANTIC
   COASTLINE THAT IS BEING REINFORCED BY THE PERSISTENT STABLE MARINE
   LAYER...THE CONVECTION WILL LIKELY BECOME ELEVATED AND POSE MAINLY A
   THREAT FOR LARGE HAIL AS IT APPROACHES THE COAST. THIS IS SUGGESTED
   BY MUCAPE VALUES IN EXCESS OF 3000 J/KG BASED ON CHATHAM MA AND
   UPTON NY 00Z SOUNDINGS...AIDED BY STEEP MID-LEVEL LAPSE RATES OVER
   7.5 C/KM. THE THREAT FOR A DMGG WIND GUST OR TWO COULD ALSO
   PERSIST...GIVEN DCAPE VALUES AOA 800 J/KG. FOR SIMILAR
   REASONS...ELEVATED CONVECTION AHEAD OF THE QLCS POSING A THREAT FOR
   MARGINALLY LARGE HAIL AND POSSIBLY GUSTY WINDS COULD IMPACT AREAS
   AROUND CAPE COD...NANTUCKET ISLAND...AND MARTHA/S VINEYARD...THOUGH
   THE MARINE LAYER IS EVEN MORE PRONOUNCED IN THESE AREAS PER SFC
   OBSERVATIONS...MITIGATING THE SVR THREAT.
   
   THE SECOND CORRIDOR OF STRONG TO SVR STORMS WILL IMPACT AREAS AROUND
   ERN MAINE IN CLOSER PROXIMITY TO THE STRONGER DEEP-LAYER FORCING
   LEADING THE SHORTWAVE TROUGH ENTERING WRN QUEBEC. A SUFFICIENT
   INFLUX OF ELEVATED INSTABILITY /00Z GRAY MAINE OBSERVED SOUNDING
   DEPICTING MUCAPE VALUE OVER 3000 J PER KG/ WILL LIKELY SUSTAIN
   ELEVATED CONVECTION ATOP THE STABLE MARINE LAYER. MARGINALLY LARGE
   HAIL WILL BE THE PRIMARY CONCERN WITH THIS ACTIVITY.
   
   ..COHEN.. 06/02/2011
   
   
   ATTN...WFO...CAR...GYX...BOX...
   
   LAT...LON   43886892 43486992 42887038 42056984 41586998 41237058
               41317129 41607153 41777200 41737249 41857269 42267268
               42667248 42787228 43347162 44967039 45227021 45886966
               46026865 45436759 44796758 44146810 43886892