LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1127 AM CDT Tue May 12 2026
Valid 121630Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
FLORIDA...PORTIONS OF THE UPPER MIDWEST...AND SOUTHEAST KANSAS INTO
WESTERN MISSOURI...
...SUMMARY...
Severe storms will be possible at least on an isolated basis across
parts of the Florida Peninsula today, and potentially from southeast
Kansas into parts of the Great Lakes late this afternoon and early
evening.
...Florida...
A very moist airmass is in place across the FL Peninsula today, with
surface observations showing dewpoints in the low to mid 70s.
Mesoanalysis estimates MLCAPE is at or above 1500 J/kg for much of
the peninsula already. A shortwave trough is currently moving into
the central Gulf Coast vicinity, with continued
eastward/southeastward progress expected throughout the day. The
prevailing buoyancy coupled with ascent attendant to this wave will
result in scattered to numerous thunderstorms. Low-level flow is
generally weak, but the shift from low-level easterly winds to
moderate southwesterly aloft is supporting moderate deep-layer
vertical shear. Some increased shear is possible in the vicinity of
the east-coast sea-breeze, with the strongest storms anticipated
near this boundary as a result. The overall expectation is for some
organized multicells and a few supercells, posing a risk of damaging
wind gusts and hail, particularly across the east-central portions
of the peninsula.
...Upper Midwest through the Mid MO Valley into southeast
KS/northeast OK...
Recent satellite imagery shows a well-defined shortwave trough
moving through the Upper Midwest towards the Upper Great Lakes.
Surface analysis places the low associated with this shortwave over
the northern MN/WI border vicinity, with an attendant cold front
extending back southwestward through northwest IA,
southeast/south-central NE, and far northwest KS. A modest
pre-frontal trough is in place just ahead of this cold front. The
shortwave trough is forecast to continue eastward, while the cold
front progresses eastward/southeastward. Northern portion of this
front (closer to the surface low and parent shortwave) will make
notably more eastward/southeastward progress than the
southern/western portion, which will move more gradually
southeastward.
Low-level moisture advection is anticipated ahead of the front, but
with mid 50s dewpoints currently in central OK, the extent and
quality of this moisture will likely be somewhat limited. Filtered
heating and mixing could also reduce dewpoints. Even so, dewpoints
will likely still reach at least the mid 40s across southern WI,
gradually increasing into the mid 50s across southeast KS/southwest
MO/northeast OK. This is expected to be enough moisture to support a
narrow corridor of modest buoyancy. Strongest ascent will be near
the surface low and shortwave trough across the Upper/Mid MS Valley,
supporting higher storm coverage than areas farther southwest. A few
high-based storms capable of wind damage and isolated hail are
possible.
Farther southwest, lower storm coverage is expected, particularly
from west-central IL into southeast KS. Thunderstorm chances across
much of this area appear low enough to remove severe probabilities.
The only exception is over the southeast KS/southwest MO vicinity.
Here, greater low to mid-level moisture could still support a storm
or two. Shear is strong enough to support hail with any storms that
mature.
..Mosier/Chalmers.. 05/12/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TSVv8G
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MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).
Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.
CONVECTIVE | TORNADO | WIND | HAIL
O'Hare International Airport KORD
(Arlington Heights South)
Chicago Executive Airport KPWK
(Arlington Heights North)
Tuesday, May 12, 2026
SPC May 12, 2026 1630 UTC Day 1 Convective Outlook
SUNRISE AND SUNSET TIMES IN UTC (if you're not logged in to Google)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)




















