Mesoscale Discussion 1221
   NWS Storm Prediction Center Norman OK
   0843 AM CDT Tue Jul 14 2020

   Areas affected...The southern Maine Coastal Region.

   Concerning...Severe potential...Watch unlikely 

   Valid 141343Z - 141515Z

   Probability of Watch Issuance...5 percent

   SUMMARY...One or two strong to severe storms are likely to persist
   through mid-day.

   DISCUSSION...A strong storm has persisted across York county for the
   last hour and is expected to persist as it moves northeastward. The
   12Z GYX RAOB is a good proximity sounding for this storm and it
   shows effective shear around 25 kts with around 1300 J/kg MUCAPE.
   Moderately steep mid-level lapse rates of 7 C/km are also aiding
   updraft acceleration and hail formation. Storm observations support
   this with MRMS MESH suggesting hail of 1.75 to 2" and some updraft
   rotation as of 1330Z. In addition, there have been a few reports of
   wind damage and hail up to 0.75" thus far. Based on this sounding,
   the storm is likely elevated, but some modest surface heating ahead
   of this storm may allow it to become surface based relatively soon.
   Modifying this 12Z RAOB for the current surface observation in
   Portland, ME of 73/65 yields 800 J/kg MLCAPE and only 50 J/kg CINH.
   Therefore, only a few more degrees of heating may erode inhibition
   enough to allow this storm to become rooted in the boundary layer.
   This storm, or additional development in its vicinity, is expected
   to persist for a few hours along the southern Maine coast, where
   breaks in the clouds have allowed for some surface heating, with a
   threat for isolated large hail and damaging winds.

   ..Bentley/Guyer.. 07/14/2020

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

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

   LAT...LON   43497087 43657071 43927032 44096989 44076950 43846936
               43616978 43457024 43287041 43247054 43257067 43297073
               43337083 43497087