Storm Prediction Center Mesoscale Discussion 1340

   Mesoscale Discussion 1340
   NWS Storm Prediction Center Norman OK
   0541 PM CDT Fri Jun 26 2026

   Areas affected...portions of northeastern Massachusetts and
   southeastern New Hampshire

   Concerning...Severe Thunderstorm Watch 397...

   Valid 262241Z - 270015Z

   The severe weather threat for Severe Thunderstorm Watch 397
   continues.

   SUMMARY...The threat for isolated large hail and damaging wind gusts
   continues across portions of Severe Thunderstorm Watch 397. This
   threat should gradually diminish this evening with the loss of
   diurnal heating and as storms progress offshore.

   DISCUSSION...Isolated convection, including one persistent
   supercell, has continued to progress southeastward across portions
   of New England and along a diffuse warm front over the past 1-2
   hours, with several reports of damaging wind gusts and large hail up
   to golf ball size noted. While the severe threat is expected to
   gradually diminish with time with the loss of diurnal heating and as
   storms progress offshore, isolated large hail (with perhaps another
   instance of large hail up to 1.5-1.75" in diameter) and damaging
   wind gusts remain possible in the meantime owing to 500 to locally
   1000 J/kg MLCAPE, strong effective shear of 50+ kts, and elongated
   hodographs.

   ..Chalmers.. 06/26/2026

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

   ATTN...WFO...GYX...BOX...

   LAT...LON   43387160 43287113 43197071 43097044 42857039 42607057
               42517089 42687160 42847203 42987207 43257195 43387160 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN