132
ACUS03 KWNS 171926
SWODY3
SPC AC 171925

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 PM CDT Thu Sep 17 2026

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN HIGH PLAINS TO THE CORN BELT AND OHIO VALLEY...AND FROM
NORTHEAST COLORADO INTO SOUTHEAST WYOMING...

...SUMMARY...
Occasional wind damage and/or large hail will be possible across
parts of the central High Plains and from the central Plains to the
Ohio Valley.

...Synopsis...
The persistent midlevel ridge over the south central CONUS will
begin to weaken as a midlevel trough moves from ID/UT to WY/CO.
There will be a belt of modestly enhanced midlevel flow from the
central Plains to the Corn Belt/OH Valley, around the northern
periphery of the ridge.  This belt of somewhat stronger flow will
coincide with a slow-moving baroclinic zone with richer low-level
moisture into the OH Valley and deeper mixing with hot surface
temperatures along/south of the front across KS/OK/TX.  Scattered
thunderstorms are probable along the front, with the strongest
storms expected during the afternoon/evening.  Water loaded
downdrafts and up to 30 kt midlevel flow suggests the potential for
occasional downbursts/wind damage across the Corn Belt/OH Valley,
while deeper mixing/inverted-V profiles will favor higher based
storms with occasional strong-severe outflow gusts across the
Plains.  Vertical shear within the warm sector will be on the lower
margins for organized severe storms, so this corridor will be
maintained as a MRGL risk.

Wind profiles and forcing for ascent will be a bit stronger across
the central High Plains, downstream from the midlevel trough
approaching the central Rockies.  There will be a conditional threat
for a couple of supercells, though uncertainty remains regarding the
magnitude of buoyancy and how much clouds will inhibit surface
heating.  Isolated large hail and strong outflow gusts will be
possible, mainly during the afternoon/evening.

..Thompson.. 09/17/2026

$$