SPC AC 140600
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Fri Mar 14 2025
Valid 151200Z - 161200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
LOUISIANNA...MISSISSIPPI...ALABAMA AND THE FLORIDA PANHANDLE...
...SUMMARY...
A tornado outbreak is possible on Saturday across the central Gulf
Coast States and Deep South into the Tennessee Valley. Numerous
significant tornadoes, and some long-track tornadoes are expected on
Saturday afternoon and evening, centered on eastern Louisiana,
Mississippi, and Alabama. Widespread damaging wind swaths and
scattered large hail are likely.
...Tornado Outbreak Possible Across parts of the Southeast on
Saturday...
...Gulf Coast States/Tennessee Valley/Southern
Appalachians/Georgia...
At mid-levels on Saturday, a strong and fast-moving jet streak will
translate eastward across the southern U.S., as an associated trough
moves through the Great Plains. Ahead of the system, a moist and
unstable airmass will be in place across the lower to mid
Mississippi Valley. Warming surface temperatures in the morning will
contribute to the development of moderate instability across much of
the moist airmass. As large-scale ascent increases ahead of the
approaching jet streak, scattered thunderstorms are expected to
initiate near the western edge of the moist airmass during the late
morning, from eastern Louisiana into northwest Mississippi and
western Tennessee. These storms should become severe rather quickly
due large-scale forcing, moderate instability and strong deep-layer
shear. Supercells with large hail, wind damage and a tornado threat
are expected to develop and move east-northeastward during the
afternoon across the central Gulf Coast States and Tennessee Valley.
The exit region of the mid-level jet streak is forecast to move
across the lower Mississippi Valley and Tennessee during the mid to
late afternoon, which will be timed well with afternoon max heating.
Forecast soundings at 21Z across parts of southern and central
Mississippi have MLCAPE in the 2000 to 3500 J/kg range, with 0-6 km
shear of 70 to 80 knots. 700-500 mb lapse rates are forecast to be
near 8 C/km, with 0-3 km storm-relative helicity in the 400 to 500
m2/s2 range. This will be very favorable for intense severe storms,
with a threat for tornadoes, wind damage and large hail. Several
tornadic supercells are expected to develop within this cluster by
mid to late afternoon as the low-level jet intensifies. Multiple
long-track high-end tornadoes will be possible. The greatest tornado
threat is expected to shift into Alabama by early to mid evening,
with a significant tornado threat also impacting parts of middle
Tennessee. In addition, supercells are expected to grow upscale into
a developing MCS, with potential to produce significant severe wind
gusts above 70 knots and large hail. The severe threat is expected
to develop eastward into parts of Georgia and the southern
Appalachians by mid to late evening. A severe threat should continue
into the overnight.
...Ohio Valley/Lower Great Lakes...
A negatively-tilted mid-level trough will move into the western
Great Lakes on Saturday, as the southern part of the trough moves
into the mid to upper Mississippi Valley. Ahead of the system,
southwest mid-level flow will be in place over most of the Great
Lakes and Ohio Valley. At the start of the period, a corridor of
rich low-level moisture is forecast from western Kentucky northward
into Indiana. Surface dewpoints along this corridor will likely
range from the mid 50s to the lower 60s F. Early in the period, a
cluster of strong thunderstorms is forecast to move across the Ohio
valley. Some of the storms could have severe potential. Wind damage,
isolated large hail and a few tornadoes will be possible. In the
wake of this activity, outflow could negatively affect the airmass
over parts of the Ohio Valley. However, areas that are not affected
by outflow could re-destabilize, maintaining a severe threat. As the
exit region of a mid-level jet moves across the Ohio Valley and
lower Great Lakes during the late afternoon, supercells will be
possible due to the increasing large-scale ascent and strong
deep-layer shear. Any supercell could have potential for tornadoes,
wind damage and hail.
..Broyles.. 03/14/2025
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