Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1239 AM CDT Thu Aug 14 2025

Valid 151200Z - 161200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...

...SUMMARY...
At least isolated severe storms may occur over parts of the northern
Plains and Upper Mississippi Valley on Friday.

...Synopsis......
An upper low will move from Manitoba toward Hudson Bay on Friday,
with minor height rises over the northern Plains as the upper trough
departs to north. An upper high will build over central Plains to
lower MO Valley, while weak troughiness persists over the Great
Basin.

At the surface, a cold front from northern MN toward the ND/SD
border will bring drying, but will stall late in the day. A large
area of instability will develop over much of SD, MN, WI, IA and NE
as dewpoints increase, and easterly surface winds will bring
moisture westward across SD and into southeast MT and northeast WY.

...Eastern SD into MN and western WI...
Storms are expected to form relatively early in the day in a warm
advection regime with southwest 850 mb winds of 30-40 kt. This
regime may favor clusters of storms with localized severe gust
potential. Modest shear could favor a few longer-lived storm cores
producing hail as well. Overall predictability is low given the
initiation regime and possibility of early day storms in the area.

...Black Hills and Vicinity...
Substantial easterly low-level flow will develop during the day as
winds back from northeast to east/southeast. This will push 60s
dewpoints as far west as southeast MT/northeast WY, beneath 30+ kt
midlevel westerly winds. This will result in elongated, straight
hodographs favorable for cellular storms producing large hail. While
storms may be quite isolated, hail could be damaging.

..Jewell.. 08/14/2025