SPC Dec 14, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook

[NorthGeorgiaWX]

SPC 0830Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0226 AM CST Thu Dec 14 2023

Valid 161200Z - 171200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE FL
PENINSULA...

...SUMMARY...
A low confidence forecast exists for Saturday evening/night, but
nocturnal tornado potential remains apparent across the Florida
Peninsula.

...FL vicinity...
A complex synoptic pattern with much greater-than-normal spread
exists across the suite of ensemble and deterministic guidance. The
degree of phasing between southern and northern-stream shortwave
troughs over the central states is quite varied. Uncertainty also
exists with how these features interact with a separate, yet to
form, shortwave impulse generated by abundant convection over the
eastern Gulf late D2/early D3, within a favorable right-rear
quadrant of an intensifying upper jet centered on the Deep South. It
is this latter feature which would likely induce cyclogenesis over
the eastern Gulf vicinity. 00Z ECMWF ensemble members continue to
indicate large spread in the degree of cyclone amplification and
track prior to 12Z Sunday. 

Non-NCEP guidance such as the deterministic 00Z ECMWF, UKMET, and
CMC are closer to the 00Z ECMWF ensemble mean and provide the
primary basis for the areal delineation of the level 1-MRGL risk for
Saturday evening/night. The initial warm-core nature of the leading
impulse suggests poor mid-level lapse rates will require sufficient 
surface-based instability coincident with the expected strengthening
low-level wind fields across the FL Peninsula. If the bulk of
guidance eventually converges to the faster/more amplified cyclone
track, a corridor of level 2-SLGT risk would seemingly be needed
given the conditional high-shear/low-CAPE setup supporting potential
for nocturnal tornadoes.

..Grams.. 12/14/2023

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