Mesoscale Discussion 1108
   NWS Storm Prediction Center Norman OK
   0120 PM CDT Sun Jul 05 2020

   Areas affected...Portions of central and southern Maine into
   southeast New Hampshire and far northeast Massachusetts

   Concerning...Severe potential...Watch unlikely 

   Valid 051820Z - 052015Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated strong to severe storms may occur through the
   late afternoon hours. A few damaging wind gusts appear to be the
   main threat, particularly with any supercell structures that
   develop.

   DISCUSSION...Visible satellite has shown recent clearing of a
   low-level cloud deck across portions of southern ME into NH,
   promoting insolation, with METAR observations depicting surface
   temperatures rising into the upper 70s/low 80s. A relatively narrow
   corridor of higher (mid 60s F) dewpoints coincides with the axis of
   stronger diurnal heating, with MLCAPE increasing into the 250-500
   J/kg range. Convective initiation appears underway across eastern NH
   into central ME, with convective coverage and intensity expected to
   gradually increase with further surface heating and buoyancy.

   35 knots of west-northwest 500 mb flow atop very weak southerly
   low-level winds suggest that 30 knots of effective bulk shear may be
   achieved across northern New England. With a relatively discrete
   storm mode expected, a few transient supercell structures are
   possible, especially where MLCAPE can exceed 750 J/kg, based on the
   12Z HREF and last few runs of the HRRR. Isolated damaging wind gusts
   and possibly some hail may occur with the stronger storms. A storm
   briefly acquiring low-level rotation also cannot be completely ruled
   out.

   ..Squitieri/Guyer.. 07/05/2020

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

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

   LAT...LON   42437140 42927164 44087130 45227029 45436994 45556969
               45586947 45556916 45486901 44686908 44256907 43796989
               42997058 42717075 42437140