163
ACUS03 KWNS 080721
SWODY3
SPC AC 080720

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 AM CDT Sat Aug 08 2026

Valid 101200Z - 111200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
NORTHERN ILLINOIS EAST-SOUTHEASTWARD INTO WESTERN PENNSYLVANIA...

...SUMMARY...
Thunderstorms with severe wind gusts will be possible on Monday from
parts of northern Illinois eastward into western Pennsylvania.
Isolated severe gusts will also be possible from parts of the
central and northern Plains into the Midwest.

...Southern Great Lakes...
A mid-level shortwave trough will move into the Great Lakes region
on Monday. At the surface, a quasi-stationary front is forecast to
be located from northern Illinois eastward into northwestern
Pennsylvania. Surface dewpoints to the south of the front are
forecast to be in the 70s F, which will contribute to moderate
destabilization by midday. Scattered thunderstorms appear likely to
develop near the front by early afternoon, with the storms moving
southeastward into the unstable air. To the south of the front,
MLCAPE is forecast to peak in the 2000 to 3000 J/kg range. In
addition, the models show moderate deep-layer shear in place which
will most likely support a mixed mode, with supercells and short
intense line segments capable of severe wind gusts. The severe
threat could continue into the mid to late evening if a cold pool
can become established and persist.

...Central and Northern Plains/Midwest...
West-northwesterly mid-level flow will be in place over much of the
north-central U.S. on Monday. At the surface, a low is forecast to
deepen over South Dakota as a cold front moves through the northern
Plains. To the south of the front, an axis of strong instability
appears likely to develop by afternoon from northern Nebraska
eastward into Iowa, where model forecasts suggest that MLCAPE could
peak in the in the 3500 to 4500 J/kg range. In addition, forecast
soundings show directional shear in the low to mid-levels, which
will contribute to moderate deep-layer shear over much of the moist
sector. This environment should support an isolated severe threat
during the late afternoon and early evening. Due to relatively weak
large-scale ascent, convective coverage is expected to be isolated,
with any severe threat remaining localized.

..Broyles.. 08/08/2026

$$