378
ACUS03 KWNS 170656
SWODY3
SPC AC 170655

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0155 AM CDT Thu Jul 17 2025

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
NORTHERN/CENTRAL PLAINS TO THE OHIO VALLEY...

...SUMMARY...
Strong to severe storms are possible from the northern and central
High Plains to the Mid-Mississippi and Lower Ohio Valleys on
Saturday.

...Mid-MS/Lower OH Valley vicinity...

Modestly enhanced westerly mid/upper flow will continue on Saturday
from the northern Plains to the Great Lakes vicinity. Convection may
be ongoing during the morning, perhaps across the Mid-MS Valley or
Lake Michigan vicinity in the form of a remnant MCS from the Day
2/Friday period. Meanwhile, a cold front will sag southward across
the Upper Midwest toward the Mid-MS valley through early Sunday.
Ahead of any ongoing convection and the front, a very moist airmass
will be in place and a corridor of strong destabilization is
forecast. While upper forcing will remain somewhat nebulous, an MCV
or outflow from morning storms could be a focus for severe
thunderstorm develop during the afternoon from the IA/IL/MO
tri-state area eastward along the moisture/instability gradient into
the Ohio Valley. Damaging gusts would be the main hazard with this
activity.

...Northern/Central Plains...

South/southeasterly low-level flow will transport rich
boundary-layer moisture northwest into western NE/SD/ND and perhaps
eastern MT along a surface trough. A shortwave ridge over the
northern Plains will shift east and weaken by evening, and 30-40 kt
mid/upper westerly flow will overspread a narrow corridor of
moderate to strong instability. While upper forcing will be
nebulous, convergence along the surface trough in the moist
low-level upslope flow regime may be sufficient for isolated strong
to severe storm development. Vertically veering wind profiles and
somewhat elongated hodographs above 3 km suggest supercells will be
possible, posing a risk for hail. Steep low-level lapse rates also
could support strong outflow winds.

..Leitman.. 07/17/2025

$$