Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Aug 20 2025 19:21:06

ACUS03 KWNS 201921
SWODY3
SPC AC 201920

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 PM CDT Wed Aug 20 2025

Valid 221200Z - 231200Z

....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS TO THE UPPER MIDWEST...

....SUMMARY...
Strong to locally severe thunderstorms are possible Friday from
parts of the central and northern High Plains into the Upper
Midwest.

....Northern/Central High Plains to Upper Midwest...

An upper cyclone over the Canadian Prairies and its attendant trough
will develop southeast across portions of the northern/central
Plains and Upper Midwest/Great Lakes on Friday. At the surface, a
cold front will develop south/southeast across the region. A
seasonally moist airmass will be in place near and ahead of the
front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead
of the front from the WY/CO High Plains eastward across parts of NE
and northeast into southern MN and northern/central WI.

Isolated to widely scattered thunderstorms are expected to develop
during the afternoon across portions of WI/MN and the U.P. of MI.
closer to the surface low over Ontario. Vertical shear is expected
to remain modest, with stronger shear likely trailing the cold
front. Nevertheless, steepened low-level lapse rates where stronger
heating occurs could support sporadic strong to severe gusts.

Additional storms are expected to develop in the post-frontal
upslope regime across parts of eastern WY and northeast CO during
the late afternoon/evening. This activity may eventually become a
forward propagating cluster across NE during the nighttime hours as
the surface cold front develops southward toward the KS border.
Forecast soundings indicated sufficient deep shear and
elongated/straight hodographs will be present amid steep midlevel
lapse rates. Isolated large hail may be possible initially, with an
increasing chance for isolated damaging gusts if sufficient
clustering can occur further east into NE and vicinity.

...Leitman.. 08/20/2025

$$

= = =
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.