792
ACUS03 KWNS 241928
SWODY3
SPC AC 241928

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0228 PM CDT Fri Jul 24 2026

Valid 261200Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE UPPER
MISSISSIPPI VALLEY INTO UPPER MIDWEST...

...SUMMARY...
Severe thunderstorms capable of mainly large hail and damaging winds
are possible from the upper Mississippi Valley and Great Lakes into
portions of the mid Missouri Valley on Sunday and Sunday night.

...Synopsis...
Enhanced mid-level flow will round the central US ridge D3/Sunday,
overspreading portions of the Midwest and Great Lakes regions. Along
with the increasing flow, several shortwave disturbances will shift
across the region. At the surface, a low will develop across the
northern Plains/Upper Midwest with a surface front moving through
the northern Plains/Midwest by the evening.

...Upper Mississippi Valley into the Great Lakes...
Beneath strong upper-level ridging and a very moist air mass with
dew points in the 60s to mid 70s, an EML plume will advect eastward
across the High Plains into the Midwest/Great Lakes region. This
will result in a very volatile and strongly unstable but largely
capped air mass. While forcing for ascent will increase, lack of
discernible surface features and strength of the capping inversion
leads to low confidence in the exact evolution of thunderstorm
development. Hi-res guidance does suggest that a few isolated
supercells may develop. A conditional threat for large to very large
hail, damaging wind, and perhaps a tornado will exist with any
storms that can become rooted within the boundary layer, given the
presence of 35-50 kt deep-layer shear and the favorable unstable air
mass.

As the front shifts south and east through the afternoon/evening and
forcing for ascent increases, storms may develop as far west as the
eastern Dakotas/Nebraska. It seems probable that a thunderstorm
complex could develop across some portion of the upper Mississippi
Valley, though confidence in the exact corridor remains low. This
will pose a conditional threat for a more focused corridor of
damaging wind potential.

..Thornton.. 07/24/2026

$$