Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Sat Mar 29 2025
Valid 291300Z - 301200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL/NORTHERN OKLAHOMA INTO SOUTHEAST KANSAS AND MISSOURI...
...SUMMARY...
Scattered severe thunderstorms should occur across parts of the
central/southern Plains into the mid Mississippi Valley, mainly this
evening through the overnight hours. This may include an organized
thunderstorm cluster across parts of northern Oklahoma into
southeastern Kansas and western Missouri capable of producing very
large hail, damaging winds, and perhaps a couple of tornadoes.
...Central/Southern Plains into the Mid Mississippi Valley...
Two mid-level shortwave troughs will impact the central/southern
Plains today, with the leading low-amplitude perturbation expected
to move quickly northeastward from the central High Plains to the
upper MS Valley by this evening. The trailing feature will advance
from northern Mexico and the Southwest across the southern High
Plains through the afternoon/evening, eventually reaching the
Ozarks/mid MO Valley by the end of the period. The primary surface
low over western KS this morning is forecast to develop
east-northeastward towards southern IA/northern MO by tonight. An
attendant cold front will sweep southward across parts of the
central/southern Plains through the period, while a dryline mixes
eastward over the southern High Plains this afternoon.
Low-level moisture is expected to continue streaming northward over
the central/southern Plains ahead of the cold front and dryline. A
substantial cap will likely inhibit robust convective development
until late this afternoon or early evening, with the cold
front/dryline intersection over western OK a potential location for
convective initiation by 23-03Z as large-scale ascent with the
trailing shortwave trough overspreads the warm sector. Moderate to
strong MUCAPE will likely be present across western/northern OK and
southern KS, with steep mid-level lapse rates atop upper 50s to mid
60s surface dewpoints. Sufficiently strong deep-layer shear is also
anticipated, which should support supercells initially, with an
associated threat for large to very large hail (potentially up to
1.5-2.5 inches in diameter). A brief window may also exist in the
early to mid evening for a tornado or two with any sustained,
surface-based supercell, as 0-1 km SRH increases in tandem with a
strengthening southerly low-level jet. Otherwise, a fairly quick
transition to a more linear/cluster mode and severe/damaging wind
threat is expected along or just ahead of the front late this
evening and overnight, as robust convection spreads northeastward
across the Ozarks and mid MS Valley before eventually weakening by
early Sunday morning.
The severe threat across southern OK into north/central TX ahead of
the front/dryline appears more conditional, as the better forcing
aloft will tend to remain farther north. Even so, given an otherwise
favorable thermodynamic and kinematic environment, large hail and
damaging winds will likely occur if any thunderstorms can initiate
and be sustained this evening/overnight. The chance of sustained
development still appears fairly low given latest guidance trends,
which supports maintaining the Marginal Risk for the conditional
severe threat with this update.
...Louisiana/Mississippi...
A remnant MCV will continue to move northeastward today across the
lower MS Valley and Mid-South. Modestly enhanced low-level southerly
flow (reference 12Z LCH sounding) should aid in the northward
transport of additional rich low-level moisture into parts of LA and
southern MS through the day. While deep-layer shear is expected to
remain fairly weak, sufficient low-level shear should be present to
support some updraft organization/rotation. Cells moving
northeastward and inland over southern LA may pose a threat for a
brief tornado or two as the boundary layer gradually destabilizes
with filtered daytime heating. Some guidance also suggests that one
or more loosely organized clusters may also have a threat for
isolated damaging winds this afternoon and early evening. Poor lapse
rates aloft, weak instability, and modest deep-layer shear should
all act to keep the overall severe threat isolated/marginal.
..Gleason/Leitman.. 03/29/2025
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