MESOSCALE DISCUSSION 1872
   NWS STORM PREDICTION CENTER NORMAN OK
   1230 PM CDT WED SEP 11 2013

   AREAS AFFECTED...HUDSON VALLEY OF NY INTO NRN NEW ENGLAND

   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

   VALID 111730Z - 111830Z

   PROBABILITY OF WATCH ISSUANCE...80 PERCENT

   SUMMARY...SEVERE THUNDERSTORM WATCH WILL LIKELY BE ISSUED SOON
   ACROSS MUCH OF NEW ENGLAND INTO THE HUDSON VALLEY OF NY.

   DISCUSSION...CU FIELD IS DEEPENING OVER HIGHER TERRAIN OF UPSTATE NY
   WHERE SFC TEMPERATURES HAVE WARMED INTO THE UPPER 80S.  CU FIELD
   WILL LIKELY CONTINUE TO EXPAND AS BOUNDARY LAYER HEATS OVER THE NEXT
   FEW HOURS.  TEMPERATURES DOWNSTREAM ACROSS VT/NH ARE QUITE WARM WITH
   READINGS NOW APPROACHING 90F...ROUGHLY CONVECTIVE TEMPERATURE BASED
   ON EARLY MORNING SOUNDINGS.  RAPID WARMING/DESTABILIZATION IS
   EXPECTED ACROSS THE REMAINDER OF NRN NEW ENGLAND PRIOR TO TSTM
   DEVELOPMENT.

   OVER THE LAST HOUR OR SO MID LEVEL CONVECTION HAS GRADUALLY DEEPENED
   ACROSS SERN QB ALONG THE ST. LAWRENCE VALLEY AND LIGHTNING IS NOW
   OBSERVED WITH DEEPER UPDRAFTS ROUGHLY 70MI NORTH OF THE VT BORDER. 
   THIS ACTIVITY IS MOVING QUICKLY EAST IN EXCESS OF 40KT AND SHOULD
   SPREAD INTO EXTREME NRN ME OVER THE NEXT FEW HOURS.  GRADUAL
   INTENSIFICATION IS POSSIBLE WITH THIS CONVECTION BUT NEW SFC-BASED
   TSTMS SHOULD EVOLVE WITHIN AFOREMENTIONED CU FIELD AND ACROSS HIGHER
   TERRAIN OF VT/NH/ME AS AIRMASS CONTINUES TO DESTABILIZE.  DAMAGING
   WINDS ARE THE PRIMARY SEVERE THREATS WITH ORGANIZED CLUSTERS/LINE
   SEGMENTS.

   ..DARROW/MEAD.. 09/11/2013


   ATTN...WFO...CAR...GYX...BOX...BTV...ALY...

   LAT...LON   44427521 47306901 45006767 41987401 44427521