756
ACUS02 KWNS 201724
SWODY2
SPC AC 201722

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 PM CDT Thu Aug 20 2026

Valid 211200Z - 221200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS...

...SUMMARY...
Scattered damaging hail (some greater than 2 inch diameter) and
severe wind gusts may occur over parts of the central Plains late
Friday afternoon and evening. Scattered storms, some with severe
wind gusts and hail, also are possible across parts of the Midwest
and Southeast.

...Central Plains...

Enhanced northwesterly flow aloft will overspread portions of the
region on Friday. Meanwhile, a plume of steep midlevel lapse rates
will shift east across the central Plains toward the Mid-MO Valley.
A corridor of rich boundary layer moisture will be in place within
east/southeast low-level flow across portions of KS/NE ahead of a
west-to-east oriented surface boundary. Moderate to strong
instability is forecast by late afternoon into evening, supporting
widely scattered thunderstorm development near the surface boundary.
Vertically veering wind profiles with elongated/straight hodographs
and 45+ kt effective shear magnitudes will support initial
supercells. Large to very large hail (some greater than 2 inches
diameter) will be possible. With time, a forward propagating cluster
could develop and move southeast across parts of NE and KS. Some
potential for severe gusts (a few near 70-80 mph) will be possible
given large instability and steep low-level lapse rates.

It is uncertain how far south the severe risk will persist into the
overnight hours. Forecast guidance, including CAMs, vary
considerably, but some potential could spread into parts of northern
OK late Friday/early Saturday. For now, have extended the Marginal
risk southward across KS to account for conditional severe
potential.

...IA/WI/IL...

Northwesterly flow aloft will modestly increase on Friday as an
upper trough deepens over the Midwest. Cooling aloft will also
result in areas of steepening midlevel lapse rates atop a seasonally
moist airmass ahead of a southeastward-advancing cold front. This
will aid in a corridor of moderate to strong destabilization across
portions of IA into northern IL and southern/eastern WI. Vertical
wind profiles will support supercell thunderstorms capable of large
hail and strong wind gusts. The southward extent of the risk into
central IL is a bit uncertain, but some risk could persist into late
evening.

...Southeast/Carolinas...

A very moist and strongly unstable airmass will be in place in the
vicinity of a surface trough Friday afternoon. Strong heating and
weak confluence will aid in thunderstorm development along the
surface trough and higher terrain. Sufficient storm coverage could
result in clustering/forward propagating as storms move eastward
through the afternoon/early evening. Otherwise, weak vertical shear
will limit overall organization, but sporadic severe/damaging gusts
could occur from wet microbursts within the unstable/high PW
airmass.

..Leitman.. 08/20/2026

$$