522
ACUS01 KWNS 031950
SWODY1
SPC AC 031949

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0149 PM CST Wed Dec 03 2025

Valid 032000Z - 041200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE UPPER TX GULF COAST INTO FAR SOUTHWEST LOUISIANA...

...SUMMARY...
A stronger storm or two is possible along the upper Texas Gulf Coast
into the Sabine Valley. Marginally severe hail could occur.

...20Z Update...
No changes to the outlook are necessary. See the previous discussion
for additional details.

..Wendt.. 12/03/2025

.PREV DISCUSSION... /ISSUED 1017 AM CST Wed Dec 03 2025/

...Synopsis...
A mid-level wave traversing the Four Corners region as of
mid-morning is forecast to move eastward into the southern Plains
through early Thursday morning. West/southwesterly mid-level flow
will steadily increase to around 50-60 knots as the wave approaches,
which will help advect a plume of modestly steep (7 to 7.5 C/km)
lapse rates out of northern Mexico towards the TX/LA Gulf Coast
region through tonight. At the surface, a weak surface low noted off
the south TX coast will gradually intensify and lift northward
towards the LA coast as broad-scale ascent ahead of the upper wave
increases later tonight. The combination of increasing ascent and
steepening lapse rates will support isolated to scattered
thunderstorms tonight into early Thursday morning for much of the TX
Coastal Plain and central to southern LA.

...Upper TX Gulf Coast to far southwest LA...
Isolated to scattered thunderstorms are expected to develop along
the upper TX Gulf Coast around 02-04 UTC tonight as warm advection
atop a residual frontal boundary increases. Forecast consensus is
that the surface low will remain off the coast through the forecast
period, which will limit the potential for surface-based convection.
However, strong moistening/ascent within the 925-850 mb layer will
likely support a narrow swath of deep convection along the TX coast
where MUCAPE may exceed 1000 J/kg. Within this zone, buoyancy
profiles should be deep enough to realize the favorable kinematic
environment, which will be characterized by elongated hodographs and
effective shear of around 50 knots. Destructive storm
interactions/modes will likely modulate the overall longevity of any
particular cell, but the sufficient thermodynamic/kinematic
environment may support a few brief strong/severe storms capable of
small to severe hail.

$$