Mesoscale Discussion 81

Issued

Feb 14, 2021, 1:20 PM EST (18:20 UTC)

Expired

Feb 14, 2021, 3:15 PM EST

In force

115 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Tampa radar (KTBW), 96 km from the middle of the area, began a volume at 18:23 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.

740 
ACUS11 KWNS 141821
SWOMCD
SPC MCD 141820 
FLZ000-142015-

Mesoscale Discussion 0081
NWS Storm Prediction Center Norman OK
1220 PM CST Sun Feb 14 2021

Areas affected...portions of central and northern Florida

Concerning...Severe potential...Watch unlikely 

Valid 141820Z - 142015Z

Probability of Watch Issuance...20 percent

SUMMARY...A band of convection with local/embedded strong
thunderstorms -- a couple of which may become capable of producing
gusty winds/minor damage or even a brief tornado -- will
develop/spread inland across portions of northern and central
Florida this afternoon.  WW is not anticipated at this time, but we
will continue to monitor the evolving risk.

DISCUSSION...A zone of ascent associated with a
complex/northeastward-moving mid-level vort max currently extends
from northern Florida to the far eastern Gulf.  Within this ascent
plume, a broken band of thunderstorms has evolved, stretching from
east of Cross City south-southwestward.  Ahead of this band, and
south of a warm front draped from near Cross City east-southeastward
to Flagler County, modest destabilization has occurred in
conjunction with some heating/steepening of low-level lapse rates,
with mixed-layer CAPE now in the 500 to 1500 J/kg range south of the
boundary.

The 18Z TBW RAOB, and latest area VWPs, reveal flow veering weakly
and increasing with height to around 50 kt at mid levels, sufficient
for a few organized storms.  Flow is expected to veer slightly with
time at low levels, and decrease gradually overall through the lower
half of the troposphere as the mid-level system shifts
northeastward/away from the region, thus trending slowly less
favorable for organized convection.  In the mean time however, the
amply unstable environment which has evolved, in conjunction with
the current flow field, suggests that a couple of stronger storms
within the convective band may become marginally severe.  In
addition, small/isolated cells are evolving inland, with at least
one of these small cells -- over southern Sumter County which will
move into southern Lake County soon -- is exhibiting weak updraft
rotation.  With flow supportive of weak rotation in additional
cells, a brief tornado cannot be ruled out through peak heating.

..Goss/Grams.. 02/14/2021

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

ATTN...WFO...MLB...TBW...JAX...TAE...

LAT...LON   27998294 28528272 29028278 29118314 29868362 30028273
            29778195 29518091 28698070 28018088 27158189 26748237
            27578282 27998294

Mesoscale Discussions in Florida, 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.