Mesoscale Discussion 1971

Issued

Dec 8, 2021, 1:34 PM EST (18:34 UTC)

Expired

Dec 8, 2021, 4:00 PM EST

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

5%

The Moody AFB radar (KVAX), 42 km from the middle of the area, began a volume at 18:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

722 
ACUS11 KWNS 081835
SWOMCD
SPC MCD 081834 
GAZ000-FLZ000-082100-

Mesoscale Discussion 1971
NWS Storm Prediction Center Norman OK
1234 PM CST Wed Dec 08 2021

Areas affected...Parts of southern Georgia...northern Florida

Concerning...Severe potential...Watch unlikely 

Valid 081834Z - 082100Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated strong to severe thunderstorm development is
possible by 3-5 PM EST, which could pose some risk for potentially
damaging wind gusts and/or a brief, weak tornado.

DISCUSSION...As a cold front slowly advances southward toward
northern Florida and adjacent portions of southeastern Georgia, a
narrow pre-frontal corridor of low-level moistening appears to have
developed weak to modest (500-1000 J/kg) CAPE with insolation.  This
has contributed to scattered mostly slowly deepening convection, but
a couple of weak thunderstorms have occasionally formed.

As a vigorous wave within stronger mid-latitude westerlies to the
north rapidly pivots from the Ohio Valley toward the Mid Atlantic
coast late this afternoon, a more subtle trailing perturbation,
within weaker cyclonic flow to the south, is digging across the the
eastern Gulf Coast states.  It is possible that associated forcing
for ascent may contribute to some enhancement of largely discrete
thunderstorm development across parts of northern Florida into
adjacent southeastern Georgia by 20-22Z. 

Although deep-layer mean wind fields and shear across this region
are expected to remain modest relative to the degree of instability,
southwesterly to westerly flow in the 850-500 mb layer, on the order
of 30-50 kt, might still be sufficient to support the evolution of a
few supercell structures.  Although these may be mostly transient in
nature, an isolated longer-lived structure appears possible, which
could pose the risk for locally strong surface gusts and/or perhaps
a brief, weak tornado.

..Kerr/Hart.. 12/08/2021

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

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

LAT...LON   30878321 31318241 31348119 30538125 29968223 29528325
            30078414 30448443 30878321

Mesoscale Discussions in Florida, 2021Mesoscale Discussions in Georgia, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.