225
ACUS02 KWNS 240521
SWODY2
SPC AC 240519

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1219 AM CDT Fri Jul 24 2026

Valid 251200Z - 261200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST...AND ACROSS PORTIONS OF
SOUTHEAST ARIZONA...

...SUMMARY...
Isolated severe storms will be possible from the northern Rockies
into the upper Midwest, and across portions of southeast Arizona.

...Synopsis...
A prominent mid-level ridge will remain anchored over central North
America with the amplification of a downstream trough across the
eastern CONUS. At the surface, ridging will be maintained over the
Northeast with a weak front along the Southeast coastal areas. That
boundary will extend northwest to low pressure over the northern and
central Plains.


...Northern Rockies...
Forcing for ascent associated with a subtle short-wave trough
cresting the ridge axis will combine with heating along the high
terrain to foster widely scattered thunderstorm development Saturday
afternoon. Area forecast soundings exhibit steep low/mid-level lapse
rates, a deeply mixed boundary layer, and MLCAPE approaching 1000
J/kg. Moreover, some enhancement of mid-level flow and resultant
vertical shear is forecast, which may support some storm
organization with the primary hazard being isolated severe wind
gusts.


...South Dakota into the upper Midwest...
Cyclogenesis is forecast over western SD along a weak front
extending from central MT into MN/WI. The air mass along and south
of the boundary in SD is expected to become quite hot with
temperatures of 100-110. And while moisture will remain limited, the
presence of steep low/mid-level lapse rates will largely contribute
to modest instability during the peak of the diurnal heating cycle.
Isolated storm development is expected by afternoon into early
evening near and south of the front atop the hot, well-mixed
boundary layer with latent cooling processes in the sub-cloud layer
potentially leading to severe outflow winds.

Farther east into MN and WI, a significantly more moist boundary
layer is expected in the vicinity of the front, yielding a
moderately to strongly unstable air mass by afternoon. However,
notable height rises are forecast with the expansion of the upper
ridge into the region, leading to uncertainty in whether
surface-based storms will develop due to the strengthening cap. On
the condition that storms develop and become sustained, seasonably
strong vertical shear will exist to support supercells with the
primary hazard being large hail. Low hail and wind probabilities
have been included in this forecast to acknowledge the conditional
threat.

Saturday night into early Sunday, there is some model signal for
elevated storm development along the nocturnal low-level jet. In
that scenario, sufficient instability and vertical shear are
expected to exist to support some severe weather risk.


...Southeast Arizona...
A slight enhancement of easterly mid-level flow is forecast across
the region, atop a modestly unstable, but steep-lapse-rate
environment. Widely scattered thunderstorms are expected to develop
over the Gila Mountains and adjacent high terrain by afternoon with
a subsequent movement toward the lower desert floor. Some cold pool
organization is possible in areas of storm clustering with an
associated risk for locally severe wind gusts.

..Mead.. 07/24/2026

$$