252
ACUS48 KWNS 130900
SWOD48
SPC AC 130858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Mon Oct 13 2025

Valid 161200Z - 211200Z

...DISCUSSION...
...Thursday/Day 4 to Saturday/Day 6...
On Thursday, a mid-level ridge is forecast to move eastward into the
Mississippi Valley, as a low and an associated shortwave trough move
northeastward into the northern Rockies and northern Plains.
Thunderstorm development is expected Thursday afternoon along and
ahead of a cold front from central Nebraska into the eastern
Dakotas. An isolated severe threat will be possible, but should be
marginal due to weak instability.

From Friday into Saturday, a large-scale mid-level trough is
forecast to move eastward from the central Rockies and Intermountain
West into the Great Plains. Scattered thunderstorms will be possible
Friday afternoon and evening ahead of the trough along and near an
axis of instability from Oklahoma northeastward into northwest
Missouri. Forecast instability and deep-layer shear appear
sufficient for an isolated severe threat.

Friday night, low-level moisture advection is forecast to markedly
increase as surface dewpoints in the lower to mid 60s F overspread
the Ark-La-Tex, Ozarks and mid Mississippi Valley. Moderate
instability is expected to develop early in the day on Saturday
across parts of the moist sector, where moderate to strong
deep-layer shear will be in place. Thunderstorms that form along and
near the axis of strongest instability should obtain a severe
threat. Supercells with severe wind gusts, hail and tornado
potential will be possible. The magnitude of the severe threat will
be greatest in areas that remain unaffected by morning thunderstorm
activity. The severe threat should spread eastward into the lower to
mid Mississippi Valley Saturday evening and into the overnight
period. Although lingering uncertainties exist, confidence in the
model solutions is great enough to add a 15 percent area over parts
of Ark-La-Tex, Ozarks and lower to mid Mississippi Valley.

...Sunday/Day 7 and Monday/Day 8...
The mid-level trough is forecast to move eastward across the lower
to mid Mississippi Valley on Sunday and to the mid Atlantic Seaboard
on Monday. Thunderstorms will be ongoing Sunday morning, ahead of a
cold front moving through the Ohio and Tennessee Valleys. New
convective development is expected during the day on Sunday ahead of
the front as surface temperatures warm. Thunderstorm development
should also occur on Monday ahead of the front. However, instability
is forecast to remain relatively weak across much of the moist
sector on Sunday and Monday, suggesting the severe threat in most
areas will remain relatively isolated.

..Broyles.. 10/13/2025