807
ACUS03 KWNS 151928
SWODY3
SPC AC 151927

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 PM CDT Fri Aug 15 2025

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA
THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES...

...SUMMARY...
Thunderstorms with potential for isolated severe wind gusts and hail
will be possible on Sunday across parts of the northern Plains
eastward into Upper Midwest and southern Great Lakes.

...Northern Plains/Upper Midwest into the southern Great Lakes...
A flattened mid-level ridge will influence thunderstorm activity on
Sunday across a large part of the CONUS.  On the northern periphery
of the ridge, a weak mid-level disturbance is forecast to crest the
ridge over the north-central states and move from SD to the western
Great Lakes.  Warm 700-mb temperatures and an associated capping
inversion will likely limit storm development across the lower MO
Valley.  A composite surface boundary, likely modulated by previous
day`s thunderstorm outflow, is forecast to be draped from the
southern Great Lakes west-northwestward into parts of the Upper
Midwest and into portions of the northern High Plains.

Showers and storms may be ongoing early Sunday morning across the
Upper Midwest in association with weak low-level warm advection in
advance of the aforementioned impulse.  Isolated to scattered
diurnal storms are forecast to focus along the low-level boundary
during the afternoon/evening given large-scale upper forcing for
ascent will remain weak to negligible.  Despite expected strong
diurnal destabilization, deep-layer shear will likely remain modest
and limit storm organization potential, with isolated severe gusts
and large hail being the severe hazards.

..Smith.. 08/15/2025

$$