Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1131 AM CDT Wed Mar 11 2026
Valid 111630Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FROM THE OHIO VALLEY AND CENTRAL APPALACHIANS TO THE
GULF COAST...
...SUMMARY...
Isolated to scattered severe thunderstorms are expected through
tonight from the ArkLaTex and Lower Mississippi Valley northeastward
through the Ohio Valley and Mid-Atlantic.
...OH Valley/Appalachians through late evening...
A surface cyclone now in southeast Lower MI will move northeastward
across the lower Great Lakes/Saint Lawrence Valley and deepen, in
advance of an amplifying northern-stream shortwave trough now over
the upper MS Valley. The warm sector of the cyclone is
characterized by boundary-layer dewpoints in the low-mid 60s into
OH/western PA/WV as of midday. Clouds/convection have been
prevalent this morning across OH/western PA in advance of a subtle
MCV, and the warmer surface temperatures have been confined to areas
immediately south of this morning convection. Additional
thunderstorm development is expected by early afternoon from
southern IN/northern KY into southern OH/WV/western PA, and storms
will spread generally eastward within the warm sector through this
evening. SBCAPE of 1000-1500 J/kg and wind profiles with long
low-level hodographs will support of a mix of line segments and
supercells capable of producing a few tornadoes and swaths of
damaging gusts before the threat begins to diminish by late evening.
...Southeast TX to MS/AL through tonight...
Thunderstorms are ongoing along a surface trough approaching
southeast TX, and additional convection extends northeastward along
a residual outflow/differential heating zone into the Ark-La-Miss.
Daytime heating/destabilization and forcing for ascent downstream
from a midlevel trough (now over the Edwards Plateau) will support a
continued increase in storm coverage/intensity this afternoon from
southeast TX into the Ark-La-Miss. Though regional soundings are
limited in the main part of the moist sector this morning, surface
observations and model forecast soundings suggest a corridor of
moderate buoyancy (MLCAPE near 1500 J/kg) through the afternoon in
advance of the ongoing storms. Deep-layer southwesterly shear,
largely oriented along the convective band, will help maintain
clusters and line segments, though embedded supercells are also
possible. Low-level hodographs will be long enough to justify the
potential for a few tornadoes with embedded circulations and/or
favorable storm mergers into the band of storms. Otherwise, wind
damage will be the main threat with the line segments through
tonight.
..Thompson/Chalmers.. 03/11/2026
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