935
ACUS03 KWNS 180704
SWODY3
SPC AC 180702

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0202 AM CDT Sat Jul 18 2026

Valid 201200Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE UPPER MIDWEST/GREAT LAKES...

...SUMMARY...
Severe thunderstorms are possible across portions of the Upper
Midwest and Great Lakes vicinity on Monday. Swaths of damaging winds
will be the most likely hazard with this activity.

...Upper Midwest/Great Lakes vicinity...

An upper shortwave trough initially over the northern Plains will
deepen as it shifts east/southeast over the Great Lakes.
Northwesterly flow aloft will increase over the region as this
occurs. A surface low will deepen as it moves across southern
Manitoba and western Ontario toward the northern Great Lakes.
Meanwhile, a trailing cold front will sweep across the Upper
Midwest, becoming oriented from northern Lower MI southwestward
toward the Lower MO Valley by Tuesday morning.

A very moist airmass (70s dewpoints) will be in place ahead of the
cold front, fostering a corridor of strong to extreme instability
across parts of southeast MN into WI and portions of the Mid-MS
Valley. Supercell wind profiles are evident in forecast soundings,
though linear forcing along the front, and the progressive nature of
the upper trough, is likely to result in a bowing line of convection
moving across the region. While all severe hazards will be possible
given the favorable thermodynamic and kinematic environment, storm
mode will likely favor a predominant risk for swaths of damaging
winds. Eastward extent of severe potential is a bit uncertain as
some guidance maintains rather strong capping toward Lake MI.
Forecast trends will be monitored, and higher probabilities may be
needed in a subsequent outlook.

...North Carolina...

Broad upper troughing will persist across portions of the eastern
U.S. on Monday, and modest west/northwest flow aloft will overspread
the southern Mid-Atlantic vicinity. A stalled surface front across
northeast NC will move north through the morning, and a very moist
and unstable airmass will be in place. Convection developing within
low-level confluence south of the surface boundary may pose a risk
for wet microbursts given steep low-level lapse rates and high PW
values.

..Leitman.. 07/18/2026

$$