Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1128 AM CDT Wed Mar 12 2025
Valid 121630Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
NORTHEAST TEXAS/SOUTHEAST OKLAHOMA INTO ARKANSAS AND NORTHWEST
LOUISIANA...
...SUMMARY...
Scattered severe thunderstorms will be possible from parts of north
Texas and southeast Oklahoma into the ArkLaTex late this afternoon
and evening. Large to very large hail and severe gusts should be the
primary hazards.
...North Texas/Southeast Oklahoma into the Lower Mississippi
Valley...
A shortwave trough with an attendant 70-90+ kt west-southwesterly
mid-level jet will advance eastward across the southern Plains
today. A related surface low should gradually consolidate over OK
and likewise develop slowly eastward through the period. Shallow
low-level moisture will continue to stream northward ahead of a
dryline that will mix eastward across parts of central TX through
late this afternoon, with surface dewpoints generally remaining in
the mid 50s to low 60s. A pronounced cap evident on the 12Z FWD
sounding will be slow to erode, and this will likely inhibit robust
thunderstorms from developing until at least late afternoon (21Z or
later). Even so, mid-level temperatures will cool through the day as
the shortwave trough approaches, and steep lapse rates aloft in
combination with daytime heating will also aid in the development of
around 1000-1750 J/kg of MLCAPE across northeast TX/southeast OK
ahead of the dryline.
While low-level winds are expected to remain fairly modest,
strengthening mid-level winds and related deep-layer shear should
support organized convection. While there is still some uncertainty
regarding how warm/moist the boundary layer will become through
heating, it seems likely that attempts at robust convective
initiation will occur by late afternoon/early evening across
north-central TX into southeast OK as convergence increases
along/near the dryline. Any convection that can develop and persist
will likely become supercellular and pose a threat for large to very
large hail (perhaps up to 2-2.5 inch diameter). Amalgamation/upscale
growth may occur with this activity through the evening across parts
of the ArkLaTex, with some risk for damaging winds with any
sustained cluster continuing eastward over the lower MS Valley
overnight. The tornado threat remains less clear, with
modest/shallow low-level moisture and generally weak low-level winds
potentially limiting factors. Still, a chance for a tornado or two
may exist with any sustained supercell this evening as a
southwesterly low-level jet gradually strengthens, especially in the
ArkLaTex region.
...Coastal Southern California...
Short-term guidance shows a low-topped band of convection will move
across parts of coastal southern CA in advance of an approaching
mid-level trough over the eastern Pacific. While a strong gust
cannot be ruled out with this activity, the overall thermodynamic
environment appears too limited for low severe probabilities.
..Gleason/Flournoy.. 03/12/2025
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