090 
ACUS03 KWNS 191933
SWODY3
SPC AC 191932

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0232 PM CDT Sat Jul 19 2025

Valid 211200Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE
NORTHERN PLAINS...AND FROM THE TENNEESSEE VALLEY TO SOUTH
CAROLINA...

...SUMMARY...
At least isolated severe storms appear likely across parts of the
northern Great Plains and parts of the Tennessee Valley into
southern Atlantic Seaboard Monday through Monday night.

...MT into the northern Plains...
A positive-tilt upper trough will remain over the Pacific Northwest
on Monday, with an upper ridge over the Plains. Moderate southwest
to west winds aloft will exist over MT and into ND and northern MN
around the periphery of the ridge, with midlevel temperatures
remaining relatively cool.

At the surface, low pressure will deepen over the central High
Plains with strong heating, and southeast winds around a Great Lakes
high will maintain a westerly push of moist air with 70s F dewpoints
across the Corn Belt. Farther northwest, lower 60s F dewpoints will
be common into much of eastern MT. This will result in strong
instability NE/IA into the Dakotas, with lack of large-scale ascent
the primary mitigating factor to a larger area of severe potential.

That said, it is likely that at least isolated severe storms develop
over western NE into the Dakotas where the air mass gets uncapped.
Conditionally, large hail and damaging winds will be possible.
Farther west into MT, this region is also likely to see at least a
few severe storms. Given the upper ridge, storm coverage and
potential capping into the evening may mitigate the overall threat.
As such, will maintain a broad area of 5% probabilities at this
time, though higher probabilities may be needed in later outlooks
cycles as predictability increases.

...TN Valley southeastward to the SC Coast...
A weak low is forecast over SC during the afternoon as a cold front
pushes south across VA and NC. The air mass across the region will
remain very moist, with pockets of stronger instability. Scattered
storms are likely within the instability axis, possibly in
association with residual boundaries from the previous night's
convection over the OH Valley. Otherwise, sufficient surface
convergence and terrain effects should support widely scattered
development from the southern Appalachians toward the SC Coast, with
locally strong to damaging downbursts in the high PWAT environment.

..Jewell.. 07/19/2025

$$