Mesoscale Discussion 0098
NWS Storm Prediction Center Norman OK
0106 PM CST Sat Feb 15 2025
Areas affected...parts of southern and eastern Arkansas and adjacent
portions of northwestern Louisiana...northwestern Mississippi and
western Tennessee
Concerning...Severe potential...Watch likely
Valid 151906Z - 152200Z
Probability of Watch Issuance...80 percent
SUMMARY...A corridor of intensifying thunderstorm development
appears likely east of the Ark-La-Tex northeastward toward the
Greater Memphis vicinity through 4-6 PM CDT. Initially this may
include a risk for supercells with potential to produce tornadoes,
before storms consolidate into an organizing line.
DISCUSSION...A baroclinic zone on the northwestern periphery of
warm, moist southerly return flow from the western Gulf has been
reinforced by persistent warm advection driven weak convective
development. Differential heating is contributing to strengthening
of the thermal gradient, and a slow northward advancement of the
front at the surface, toward the Memphis TN, Pine Bluff and El
Dorado AR vicinities. Surface observations indicate that a focused
area of stronger surface pressure falls (2-3+ mb/2 hourly) is
already developing to the west/northwest of Little Rock as of 18Z,
and models indicate that this boundary will become the focus for
strengthening surface cyclogenesis later this afternoon into
tonight.
Upstream, it appears that a significant approaching short wave
trough will maintain a general positive tilt as it progresses
eastward across the southern Great Plains into early evening.
However, models suggest that increasingly difluent/divergent flow
ahead of it will contribute to increasing forcing for ascent along
the frontal zone by 21-23Z.
Although it is possible that this may remain largely focused
above/just to the cool side of the front, there may be a window of
opportunity for sufficient weakening of mid-level inhibition, in a
narrow corridor just ahead of the front, to support thunderstorm
initiation rooted within an unstable boundary-layer characterized by
CAPE up to 1000 J/kg. Within this regime, low-level hodographs,
beneath 50+ kt south-southwesterly flow around 850 mb, are already
sizable and clockwise curved, and conducive to the evolution of
strong low-level mesocyclones with the potential to produce
tornadoes.
..Kerr/Smith.. 02/15/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MEG...JAN...LZK...SHV...
LAT...LON 35129106 35688911 34958950 34329039 33089205 32119322
32039392 33049363 33889275 35129106
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