Mesoscale Discussion 0850
   NWS Storm Prediction Center Norman OK
   0946 AM CDT Sat Jun 06 2020

   Areas affected...South-Central/Southeast ME...Southern NH...Southern
   VT...Much of MA

   Concerning...Severe potential...Watch possible 

   Valid 061446Z - 061645Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Increasing thunderstorm coverage is expected over the next
   few hours. Strong to severe storms capable of hail and damaging wind
   gusts are possible.

   DISCUSSION...Recent surface analysis places a low over central ME,
   with a cold front extending southwestward through northern NH,
   central VT, and upstate NY. This cold front is preceded by a weak
   trough and attendant wind shift. Mid-level lapse rates ahead of the
   front are weak but warm and moist low-levels will still help support
   moderate to strong instability. Surface temperatures already range
   from the low 70s across southern ME to the upper 70s/low 80s across
   western MA. Dewpoints range from the low 60s in ME to the upper 60s
   across MA. The cold front is expected to continue eastward into this
   warm, moist, and unstable air mass, contributing to an increase in
   thunderstorms. Additionally, forcing for ascent will be augmented by
   the approaching shortwave trough. Based on recent VAD and
   mesoanalysis data, effective bulk shear is already around 50 kt.
   Some increase in vertical shear is possible as stronger mid-level
   winds attendant to the shortwave trough move through. 

   All of these factors create an environment supportive of strong to
   severe thunderstorms from now through the afternoon. Pre-frontal
   storm mode will likely be cellular, with a few supercells possible.
   A more linear mode is anticipated along the front, with strong wind
   gusts as the primary severe risk. Portions of this area will likely
   be upgraded to Slight Risk for the upcoming 1630Z Outlook and
   convective trends will be monitored for possible watch issuance.

   ..Mosier/Thompson.. 06/06/2020

   ...Please see www.spc.noaa.gov for graphic product...

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

   LAT...LON   42747376 44637121 45186896 44336851 43726951 43217030
               42107106 42137336 42747376