Mesoscale Discussion 1970
   NWS Storm Prediction Center Norman OK
   1249 AM CST Wed Dec 08 2021

   Areas affected...Central portions of the FL Panhandle

   Concerning...Severe potential...Watch unlikely 

   Valid 080649Z - 080845Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Potential may continue another hour or two for isolated,
   nearly surface-based supercell formation in a band of convection
   extending west-southwest/east-northeast across the discussion area. 
   In a marginally favorable environment, a brief tornado may occur. 
   The threat appears too isolated, short-lived and conditional for a
   watch.

   DISCUSSION...At 0630Z an isolated, weakening supercell was noted
   over eastern Walton County, just onto the cool side of a
   quasistationary to weakly warm frontal zone.  This activity was in
   the eastern part of a loosely organized band of convection extending
   west-southwest past Ft. Walton Beach.  That boundary was analyzed
   from there west-southwestward toward the mouth of the Mississippi
   River, and extends northeastward into cooler air on both sides over
   southern GA.  A baroclinic/marine boundary extends from near the
   convection southeastward across Apalachee Bay, south of which
   optimal maritime/tropical air should remain.

   Both boundaries are expected to drift northward at a slower pace
   than the net poleward motion of convection developing along or to
   their north in the band of greatest lift.  As such, the remains of
   the supercell, which produced a brief apparent TDS around 610Z,
   should move obliquely over a more-stable boundary layer with time
   and remain more disorganized, but may be sustained as elevated
   convection atop the shallow near-surface stable layer farther
   east-northeast and inland.

   Additional/trailing development may occur in an environment of weak
   MLCINH and low LCL, though low-level convergence is modest due to
   the weak near-surface winds. The modified 00Z TLH RAOB and forecast
   soundings suggest MLCAPE around 250-500 J/kg along the southward
   side of the boundaries, increasing above 500 J/kg over the Gulf. 
   Effective SRH from RAP soundings is generally under 100 J/kg, but
   may be locally near 150-175 J/kg where effectively surface-based
   parcels extend inland, based on the Eglin VWP.

   ..Edwards.. 12/08/2021

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

   ATTN...WFO...TAE...MOB...

   LAT...LON   30418559 30398617 30368641 30788587 30608500 30378516
               30418559