Mesoscale Discussion 1838
   NWS Storm Prediction Center Norman OK
   0404 AM CST Mon Dec 07 2020

   Areas affected...The FL Keys and extreme south FL Peninsula

   Concerning...Severe potential...Watch unlikely 

   Valid 071004Z - 071130Z

   Probability of Watch Issuance...5 percent

   SUMMARY...An eastward-moving cluster may pose a risk for 40-60 mph
   wind gusts as it spreads east from the Dry Tortugas across the Keys
   through about 13Z. Additional showers forming over the Upper Keys
   might deepen into a supercell, but more likely should over the
   Florida Straits.

   DISCUSSION...A longer-lived convective cluster/short-line segment
   near the Dry Tortugas has been steadily moving east around 35 kt.
   This activity will likely spread across much of the Keys between
   11-13Z. While surface winds are predominately southwest across the
   Keys, robust speed shear with a nearly unidirectional wind profile
   as indicated by the Key West VWP may support embedded small-scale
   bowing segments capable of producing strong surface wind gusts amid
   1000-1500 J/kg of MLCAPE per 06Z Key West and 08Z Miami RAOBs. 

   A confluence band of showers has also recently formed in a
   north/south-orientation just east of the longitude of Marathon.
   Surface winds have become increasingly veered across the greater
   Miami metro area since the 08Z sounding, which is a trend also noted
   in time-series of the VWP. That has likely resulted in decreasing
   low-level hodograph curvature. Nevertheless, it is possible that a
   transient supercell may develop out of this band of showers, before
   they shift east off the coast into the Straits.

   ..Grams.. 12/07/2020

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

   ATTN...WFO...MFL...KEY...

   LAT...LON   24818208 25158123 25318078 25478023 25348014 24868032
               24568089 24438162 24448216 24818208