058
ACUS48 KWNS 170855
SWOD48
SPC AC 170854

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0354 AM CDT Sun Aug 17 2025

Valid 201200Z - 251200Z

...DISCUSSION...
...Wednesday/Day 4 to Friday/Day 6...
On Wednesday, a mid-level ridge will likely be in place across the
northern Plains. At the surface, a front is forecast to be located
over the Ozarks and lower Ohio Valley. Moderate instability is
expected to develop to the south of the front, and over parts of the
north-central states. In areas where storms are expected, deep-layer
shear should be weak, suggesting a severe threat is unlikely.

On Thursday, a mid-level shortwave trough and an associated cold
front are forecast to move eastward into the northern Plains. An
axis of moderate instability is forecast ahead of the front. This
combined with moderate deep-layer shear could be enough for an
isolated severe threat during the afternoon and evening, mainly over
eastern North Dakota and northwestern Minnesota.

The front and its associated shortwave trough are forecast to move
into the upper Mississippi and mid Missouri Valleys on Friday.
Moderate instability appears likely to develop ahead of the front
during the afternoon. Along and near the instability axis, the
greatest potential for thunderstorm development could occur in the
central Plains within northwest mid-level flow. An isolated severe
threat will be possible during the late afternoon and early evening.

...Saturday/Day 7 and Sunday/Day 8...
On Saturday and Sunday, an upper-level trough is forecast to remain
over the Great Lakes region. Ahead of the trough, an axis of
instability is forecast to develop in the central Appalachians,
where isolated to scattered thunderstorms will be possible each
afternoon. Moderate deep-layer shear could be sufficient for an
isolated wind-damage threat, mainly in the late afternoon as
low-level lapse rates become steep.

..Broyles.. 08/17/2025