229
ACUS03 KWNS 181927
SWODY3
SPC AC 181926

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 PM CDT Fri Sep 18 2026

Valid 201200Z - 211200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN PLAINS TO THE OHIO VALLEY...AND EAST OF THE COLORADO FRONT
RANGE...

...SUMMARY...
Isolated severe thunderstorms, accompanied by mainly a wind and hail
threat, are possible across portions of the central High Plains, the
southern Plains, and the Midwest to Ohio Valley on Sunday.

...Synopsis...
In the wake of a northern stream shortwave trough crossing New
England, a surface cold front will move southeastward into the
Mid-Atlantic, lower OH Valley and southern Plains by early Monday.
The frontal location will be modulated by prior convective outflows,
and it will reside beneath a belt of somewhat enhanced (~30 kt)
midlevel flow with embedded perturbations.  Predictability of
thunderstorm clusters is low in this flow regime, so will maintain
low severe probabilities along the frontal zone where steep
low-level lapse rates and water loaded downdrafts will favor the
potential for a few strong-severe outflow gusts.

Upslope flow will help keep low-level moisture close to the Front
Range, with cooler temperatures and weaker buoyancy/stronger
convective inhibition farther east into the Plains.  The passage of
a weakening midlevel trough during the afternoon will provide weak
ascent and sufficient deep-layer vertical shear for supercells
capable of producing isolated large hail and strong outflow gusts.

..Thompson.. 09/18/2026

$$