SPC MD 1699

MD 1699 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST GA AND EXTREME NORTH FL

Mesoscale Discussion 1699
NWS Storm Prediction Center Norman OK
1118 PM CDT Wed Sep 16 2020

Areas affected...Southeast GA and extreme north FL

Concerning...Severe potential...Watch unlikely 

Valid 170418Z - 170615Z

Probability of Watch Issuance...20 percent

SUMMARY...A low-end tornado threat will persist overnight near the
warm front, in advance of the remnants of Sally, but a tornado watch
does not appear necessary.

DISCUSSION...Occasional small supercell structures have been
observed with cellular convection forming in both the primary
confluence band near the FL Big Bend, and along the surface warm
front near the southeast GA coast.  The stronger wind profiles and
associated vertical shear will tend to spread northeastward across
GA overnight, east of the weakening surface center of tropical
cyclone Sally.  The most favorable hodograph curvature/SRH for
tornadic storms will be along the warm front, but surface-based
buoyancy will remain rather weak across inland areas of south
central/southeast GA, with the richer theta-e (surface temperatures
and dewpoints in the mid 70s) confined to the coast.  Given the
sub-optimal phasing of the buoyancy and vertical shear, and
horizontal advection as the primary source for destabilization
inland overnight, the tornado threat should remain somewhat
limited/transient.  As such, a tornado watch does not appear
necessary.

..Thompson.. 09/17/2020

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

ATTN...WFO...CHS...JAX...FFC...TAE...

LAT...LON   31658108 30938184 30808247 30408314 30418355 31018367
            31428356 31718348 31818285 32018215 32188137 31998110
            31658108 

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