Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0759 PM CDT Tue Sep 15 2026

Valid 160100Z - 161200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
WESTERN TEXAS AND NORTHWESTERN OKLAHOMA TO THE SOUTHERN GREAT
LAKES...

...SUMMARY...
A couple of severe thunderstorms, accompanied by a severe wind and
hail threat, remain possible this evening across the southern High
Plains to the southern Great Lakes.

...Synopsis...
A broad upper ridge remains in place across the central and eastern
CONUS, with a low-amplitude trough currently located over the
Pacific Northwest. Ahead of the upper trough, a 500 mb jet streak,
accompanying a mid-level impulse, is currently overspreading the
Upper MS Valley. As a result, weak surface troughing and northward
low-level moisture advection are supporting a band scattered
thunderstorms along the west-northwestern periphery of the upper
ridge. Stronger flow aloft glancing the upper ridge periphery, amid
moderate buoyancy, will support a few strong to severe thunderstorms
for a few more hours, from the southern High Plains to the Lower
Great Lakes.

...Southern High Plains...
Pulse cellular and multicellular clusters, with a history of severe
gusts, continue to traverse a mixed boundary layer, characterized by
low to mid 90s F surface temperatures. Despite the persistent warm
temperatures, nocturnal cooling should eventually reduce severe gust
potential. In the meantime, 1500+ J/kg DCAPE will promote adequate
evaporative cooling potential with the stronger storm cores to
support a short-duration severe gust threat.

...Northwestern OK to the southern Great Lakes...
Scattered to widespread thunderstorms remain in progress along the
west-northwest periphery of the upper ridge. Given the 500 mb jet
streak over the Upper MS Valley, 30-40 kts of effective bulk shear
is overspreading the upper ridge periphery, especially over northern
MO, where the strongest storms are currently located. 1000-2000 J/kg
MLCAPE overlapping the aforementioned shear will continue to promote
multicellular clusters and a couple of supercells, accompanied by a
severe wind and hail threat for at least a few more hours.

..Squitieri.. 09/16/2026