ACUS01 KWNS 230600
SWODY1
SPC AC 230559

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Tue Sep 23 2025

Valid 231200Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN PLAINS AND OZARKS TOWARD THE MID MISSISSIPPI VALLEY...

...SUMMARY...
Severe storms are possible from the southern Plains to the Mid
Mississippi Valley today and tonight. Supercells capable of all
severe hazards are possible mainly from eastern Oklahoma into the
Ozarks. Additional isolated severe storms with damaging gusts are
possible over the Mid Atlantic.

...Eastern Oklahoma into the Ozarks and northeast Texas...
A positive tilt large-scale trough will amplify over the southern
Rockies and High Plains today, as several small-sale features
embedded within the stronger westerly flow pass across KS/OK, over
the Ozark Plateau and into the mid MS Valley today and tonight.
Accompanying the lead shortwave, a 40-50 kt mid-level jet will aide
in surface cyclogenesis along a southward moving cold front across
the KS/OK border. Near the surface low, an early morning MCS will
likely be moving into northwest AR and southwest MO ahead of a 30-40
kt low-level jet. Isolated damaging winds and perhaps some hail will
be possible with this initial activity. Some resurgence is possible
through the morning along the AR/MO border with diurnal
destabilization, especially along the southern flank. Regardless,
outflow from the morning convection will likely develop into an
east-west oriented effective boundary intersecting with the
developing surface low from the AR/MO border region into eastern OK.

As the shortwave trough approaches, robust destabilization is
expected over much of the warm sector owing to heating amidst 70s F
surface dewpoints. Afternoon MLCAPE of 2000-3000 J/kg should support
rapid thunderstorm development along the per-frontal surface
trough/wind shift and near the effective boundary. Semi-discrete
supercells are expected with a continued 30+ kt southwesterly
low-level jet helping to expand hodographs. Damaging gusts and some
hail (occasional 2+ inch) are possible with initial storms from
eastern OK into northeast TX where low-level flow is more veered and
lapse rates are steeper. Tornado potential (conditionally
significant) is likely to be maximized near the effective triple
point and modifying outflow boundary from northeastern OK into
western AR. Here, backed low-level flow, ESRH of 200-300 m2/s2 and
the potential for higher low-level buoyancy could support locally
stronger low-level mesocyclones. Higher tornado probabilities may be
needed as confidence in final boundary positioning and
destabilization, post MCS, becomes more clear.

Upscale growth into one or more clusters is expected into the early
overnight hours across eastern AR into the Mid MS Valley. Some risk
for damaging winds and perhaps an embedded tornado or two may
persist. However, increasingly strong low-level warm advection ahead
of the deepening surface low should support widespread thunderstorm
development which may limit instability.

...Mid Atlantic...
Downstream of a broad mid-level trough, widely scattered
thunderstorms are expected to develop by early afternoon within a
moist/moderately unstable air mass east of the central Appalachians
toward the mid Atlantic. Around 20-30 kt of deep-layer shear may
promote a couple loosely organized clusters with a risk of locally
damaging gusts before weakening into the evening hours.

...Central TX...
As the surface low deepens and moves eastward, the cold front will
continue southward across the TX Panhandle into central TX
overnight. The primary upper trough over the southern Plains will
pass overhead with moderate height falls and cooling aloft.
Low-level isentropic ascent could support a few elevated storms
along and north of the front with damaging wind and hail potential
overnight.

..Lyons/Hart.. 09/23/2025

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