873
ACUS01 KWNS 101957
SWODY1
SPC AC 101956

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Sun Aug 10 2025

Valid 102000Z - 111200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE CENTRAL AND SOUTHERN PLAINS...

...SUMMARY...
Scattered severe thunderstorms are possible across parts of the
central/southern Plains through tonight, with large hail and
damaging winds the main threats.

...20z Update Front Range...
Initial thunderstorms should continue to develop over the higher
terrain of eastern CO and the Front Range as a broad upper trough
shifts eastward and low-level upslope flow continues this afternoon.
1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will
support supercells. Steep mid-level lapse rates and cooler mid-level
temperatures will favor an initial risk for hail before upscale
growth results in an MCS tonight. Damaging gusts are possible into
parts of the southern Plains. Have expanded the Slight Risk farther
north/east where development is possible closer to the WY/CO border.


...Mid Mississippi Valley...
Diurnal heating ahead of the weak cold front over the Midwest will
continue to support moderate destabilization this afternoon. Ongoing
thunderstorm clusters should gradually expand eastward as cold pools
deepen. While vertical shear will not be strong, (generally less
than 20 kt) an occasional damaging gust remains possible over parts
of IL, MO and WI. Have expanded the Marginal risk eastward to cover
the low-end risk. Otherwise, see the prior outlook for additional
info.

..Lyons.. 08/10/2025

.PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/

...CO/KS...
Morning water vapor loop shows a vigorous shortwave trough digging
southeastward into central CO.  Large scale forcing for ascent ahead
of this trough will aid in the development of scattered
thunderstorms along the foothills of central CO by early afternoon,
with storms spreading eastward through the afternoon/evening.  Ample
low-level moisture and CAPE are present over eastern CO/western KS
to promote a few intense cells, with favorable westerly flow aloft
for supercell structures. Large hail is the main concern, with an
increasing risk of damaging winds with eastward extent this evening.
 A tornado or two is possible as storms interact with a remnant
outflow boundary that extends across the TX Panhandle and northwest
OK.

...MO/IL/WI...
A corridor of strong heating will encourage scattered thunderstorm
development this afternoon from southern MO into central/northeast
IL.  Weak winds aloft and considerable mid-level moisture will limit
overall downdraft potential.  Nevertheless, gusty/damaging winds
could occur with the strongest cells.

...Southeast AZ...
Similar to yesterday, scattered high-based afternoon/evening
thunderstorm development is expected over southeast AZ in a
hot/unstable environment.  The strongest cells may produce locally
damaging wind gusts.

$$