799
ACUS03 KWNS 211913
SWODY3
SPC AC 211912

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0212 PM CDT Thu Aug 21 2025

Valid 231200Z - 241200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorm potential currently appears low on Saturday.

...Central High Plains into Lower MI vicinity...

The upper cyclone over Ontario will deepen modestly but mostly
remain stationary, while an attendant shortwave trough deepens
across the Midwest on Saturday. Stronger westerly flow will be in
place across the Upper Midwest/Great Lakes as a surface cold front
develops east/southeast across MI and much of the MS/OH Valleys and
portions of the southern Plains. A seasonally moist airmass will be
in place ahead of the cold front, with pockets of modest
destabilization expected from the central High Plains into the Lower
MI Vicinity. Generally weak midlevel lapse rates and poor frontal
convergence will limit thunderstorm coverage, but a few storms could
develop across Lower MI and perhaps parts of IN/OH. Gusty winds
could accompany these storms, but overall severe potential appears
low.

Additional thunderstorms also will develop over higher terrain in
parts of southeast WY into eastern CO, southward toward the Raton
Mesa vicinity, and perhaps eastward into northern OK near the
frontal boundary. The best chance for a strong storm or two appears
to be over eastern CO in the post-frontal upslope regime where
around 1000 J/kg MLCAPE will be present amid supercell wind profiles
and steep lapse rates. Modest warming near 700 mb may suppress
updraft intensity, especially amid weak large-scale ascent. If a
stronger storm can be maintained off of the higher terrain, strong
gusts and hail could occur. However, confidence in this scenario is
low, precluding severe probabilities.

..Leitman.. 08/21/2025

$$