Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0655 AM CST Wed Nov 11 2026

Valid 111300Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
EASTERN ILLINOIS INTO INDIANA...WESTERN/CENTRAL KENTUCKY...AND
MIDDLE TENNESSEE...

...SUMMARY...
Thunderstorms capable of producing isolated hail, damaging winds,
and perhaps a tornado may occur this afternoon and evening across
parts of eastern Illinois into Indiana, western/central Kentucky,
and middle Tennessee.

...Midwest/Lower Ohio Valley into Middle Tennessee...
Recent water vapor satellite imagery shows a mid-level shortwave
trough digging southeastward over the Upper Midwest towards the mid
MS Valley, with recent elevated thunderstorm development noted over
eastern IA capable of producing small hail (reference ~300 J/kg
MUCAPE in the 12Z observed DVN sounding). A related weak surface low
will develop from southeast IA this morning to the IN vicinity by
late afternoon/early evening. A trailing cold front will continue
advancing east-southeastward across the southern Plains, mid MS
Valley/Mid-South, and lower OH Valley this afternoon and evening.
The main uncertainty and likely limiting factor to severe potential
today remains shallow/limited low-level moisture ahead of the front
across the Midwest/lower OH Valley, where latest surface
observations show dewpoints generally in the 30s to mid 40s.
Somewhat greater low-level moisture associated with a modified
continental polar airmass is present across the southern Plains into
the Ozarks/lower MS Valley. But, west-northwesterly low-level flow
noted in area VWP trends and forecast low-level trajectories suggest
this moisture will struggle to advect northward through the day,
perhaps reaching parts of middle TN/southern KY. Therefore, most
guidance appears a bit moist with boundary-layer dewpoints and
related instability this afternoon, although some mid-level
moistening could occur.

Current expectations are for surface-based thunderstorms to
initially develop over eastern IL by 18-21Z, with additional
development possible with southward extent along/ahead of the front
in western/central KY through the afternoon/early evening as the
boundary layer gradually destabilizes. The combination of weak, but
potentially sufficient, MLCAPE and 30-40 kt of deep-layer shear
oriented largely orthogonal to the surface cold front should support
updraft organization. A mix of clusters and marginal supercells are
expected to evolve and spread quickly eastward while posing an
isolated threat for hail and damaging winds given cold mid-level
temperatures and modestly steepened low-level lapse rates. However,
the lack of greater low-level moisture/stronger instability should
tend to limit the overall severe threat. Modestly enhanced low-level
shear may also support a tornado risk, especially if a supercell can
develop and be sustained. But, tendency for low-level flow to veer
to westerly should reduce effective SRH with time through the late
afternoon/evening. The isolated severe risk should wane this evening
with eastward extent across the lower OH Valley as instability
diminishes with the loss of daytime heating.

...Central/Southern Florida Peninsula...
Isolated to scattered thunderstorms should preferentially form along
the Atlantic Coast sea breeze this afternoon across the
central/southern FL Peninsula. Glancing large-scale ascent
associated with a weak mid-level perturbation over the Southeast
should aid this convective development, but multiple inversions
aloft noted in the 12Z observed MFL/TBW soundings should tend to
limit updraft intensities. Still, small hail and gusty winds could
occur with the stronger cores given the presence of moderate
instability and 30-35 kt of deep-layer shear.

..Gleason/Wendt.. 11/11/2026

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0400 AM CST Wed Nov 11 2026

Valid 141200Z - 191200Z

...DISCUSSION...
Over the coming weekend, a mid-level shortwave trough will move from
the Desert Southwest into the southern Plains. Ahead of the trough,
moisture advection is forecast across much of Texas and Oklahoma,
where surface dewpoints could increase into the 50s and 60s F. This
would contribute to weak instability over parts of the southern
Plains Sunday afternoon. Uncertainty exists on where the northern
extent of the instability will be but it seems likely that enough
instability will be in place by late Sunday afternoon for an
isolated severe threat in parts of central and north Texas. As the
system moves eastward across the Southeast from Monday to Wednesday,
thunderstorms will be possible ahead of the trough each day from the
central Gulf Coast to the Florida Peninsula. The best chance for an
isolated severe threat would be on Wednesday over the Florida
Peninsula where an unstable airmass is forecast as the trough
passes.