Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1226 AM CDT Wed Oct 28 2026

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
EAST-CENTRAL MINNESOTA AND WEST-CENTRAL WISCONSIN....

...SUMMARY...
A few severe thunderstorms are possible over the Upper Mississippi
Valley on Wednesday with some tornado potential. Isolated large hail
and damaging winds will also be possible.

...Synopsis...
The overall mid-level pattern across the CONUS will become more
zonal through the day today. Within this more zonal pattern, a
mid-level shortwave trough will traverse the northern Plains. A weak
surface low, associated with this mid-level trough, will deepen as
it moves northeastward through the day. Elsewhere, high pressure
will dominate through the day and evening. 

...Upper Mississippi Valley...
Low-level moisture will advect northward today as a surface low,
currently analyzed across southeast Colorado, deepens and moves
northeastward to the Upper Midwest. This will result in weak
instability into southern and central Minnesota with dewpoints in
the upper 50s. During peak heating, storms are expected to develop
near this surface low within the weakly unstable zone. Veered wind
profiles and strong deep-layer shear will support a discrete mode
including the potential for supercells. In fact, wind profiles are
quite favorable within this zone with instability being the primary
limiting factor. However, it would only take an increase of a few
degrees in the dewpoint and/or temperature for greater instability
and potentially a more impactful event. Therefore, while the
forecast remains conditional, the ceiling could involve strong
tornado potential. Therefore, added a Slight Risk, driven by tornado
probabilities, for a small portion of eastern Minnesota and western
Wisconsin in the vicinity of the surface low near peak heating where
a several hour window of severe weather potential may exist. Shear
and storm mode will support some hail potential, but the overall
weaker instability precludes higher probabilities. The greatest
damaging wind potential will likely be along the warm front ahead of
the surface low where the potential for upscale growth is the
greatest. However, even within this zone, the wind threat should
remain somewhat subdued given the weak instability along this zone.

..Bentley/Halbert-E.. 10/28/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1218 AM CDT Wed Oct 28 2026

Valid 291200Z - 301200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected on Thursday.

...Southern Rockies to Southern Plains vicinity...

Upper ridging will begin the period over the southern/central Plains
to the Mid/Lower MS Valley vicinity. The ridge will weaken across
the southern Plains as a shortwave impulse ejects from northern
Mexico into TX/NM. Meanwhile, another shortwave upper trough will
move east across the Great Lakes vicinity. At the surface, a cold
front will extend from the upper Great Lakes to central KS Thursday
morning. The northern extent of the front will continue to develop
east/southeast across portions of the Midwest, while the western
extent of the front advances northward across the central Plains
within the low-level warm advection regime beneath the upper ridge.

Southerly low-level flow will transport modest boundary layer
moisture northward across TX/OK/KS and the Lower MO Valley. This
will support generally modest destabilization in the 500-1000 J/kg
MLCAPE range, though a few areas across OK/KS may see values
approaching 1500 J/kg. Showers and thunderstorms are expected to
develop within the broad warm advection regime, aided by modest
large-scale ascent from the ejecting weak midlevel trough, from
NM/TX into OK/KS from midday into the evening. Vertical shear is
forecast to remain weak, limiting organized strong/severe
thunderstorm potential despite modest instability.

..Leitman.. 10/28/2026

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0144 AM CDT Wed Oct 28 2026

Valid 301200Z - 311200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorm potential appears low on Friday.

...Synopsis...

Showers and thunderstorms will again be possible on Friday across
portions of the south-central U.S. as a weak midlevel shortwave
trough continues to slowly lift northeast across the
southern/central Plains. Weak instability and limited vertical shear
will preclude severe thunderstorm potential. 

Further west, southerly low-level flow will maintain 50s to near 60
F surface dewpoints across southern AZ as a weak upper shortwave
trough moves across the Lower CO Valley and Southwest. Cool
temperatures aloft will support steep midlevel lapse rates atop the
relatively moist boundary layer, fostering areas of modest
destabilization. Isolated to scattered thunderstorm development will
be possible, though deep-layer shear is expected to remain somewhat
weak (15-25 kt effective shear). Currently, severe thunderstorm
potential appears limited, but a stronger storm or two could produce
small hail. Trends bear watching as any uptick in instability or
strengthening shear could support a more isolated risk for severe
thunderstorms across southern/central AZ.

..Leitman.. 10/28/2026