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Mesoscale Discussion 656
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   Mesoscale Discussion 0656
   NWS Storm Prediction Center Norman OK
   1139 AM CDT Thu May 21 2020

   Areas affected...portions of the central and southern FL Peninsula

   Concerning...Severe potential...Watch unlikely 

   Valid 211639Z - 211845Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A couple of strong storms could briefly become severe this
   afternoon across the central and southern Florida peninsula.
   Sporadic hail and strong gusts are possible with the most intense
   cells, however the overall threat will remain limited and a watch is
   not expected.

   DISCUSSION...Isolated thunderstorms are developing early this
   afternoon in low level convergence as the seabreeze develops across
   the southern FL Peninsula. A very moist airmass is in place, with
   surface dewpoints generally from 70-75 F and PW values greater than
   1.5 inches. Strong heating has resulted in temperatures warming into
   the upper 80s to low 90s beneath steep midlevel lapse rates (7-7.5
   C/km), leading to MLCAPE values greater than 2000 J/kg. 12z regional
   RAOBS and a recent 15z RAOB from XMR show very weak vertical winds,
   with effective shear values generally less than 15-20 kt. This is
   not expected to change throughout the day. As a result, convection
   will generally be disorganized, and intense updrafts short-lived.
   Nevertheless, strong instability and moderate lapse rates could
   result in a few instances of marginally severe hail. Furthermore,
   steep low level lapse rates in this very moist low level environment
   could lead to a couple of strong, locally damaging gusts. Overall,
   convection will be pulse-like in nature and threat is expected to
   remain limited.

   ..Leitman/Hart.. 05/21/2020

   ...Please see for graphic product...


   LAT...LON   28798120 28508085 28238072 28028065 26748017 25978028
               25888040 25758062 25738077 25778098 26058127 26358147
               26688169 27558183 27758183 28268168 28548157 28728147
               28788135 28798120 

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