LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1220 AM CDT Fri Oct 17 2025
Valid 171200Z - 181200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OK
INTO CENTRAL/EASTERN KS AND WESTERN MO...
...SUMMARY...
Thunderstorms with isolated hail and strong to severe wind gusts
will be possible this evening through the overnight period from the
southern and central Plains into the lower Missouri Valley.
...Synopsis...
A mid/upper-level cyclone initially near the ND/MB border will move
northeastward through the day, as a trailing positive-tilt trough
and attendant weak cold front move eastward across the Upper Midwest
into the central/southern Great Plains. A mid/upper-level shortwave
near the base of this trough is forecast to amplify by late in the
period across the southern Rockies. Farther northwest, an upstream
shortwave trough and vigorous mid/upper-level jet will dig
southeastward across the northern Rockies late tonight.
...Parts of the southern/central Plains into the lower MO Valley...
Weak to locally moderate destabilization will be possible by late
afternoon from parts of the southern/central Plains into the lower
MO Valley, along/ahead of the weak surface trough/front. Generally
weak midlevel lapse rates and modest large-scale ascent will tend to
limit diurnal storm potential, but isolated strong-storm development
cannot be ruled out by early evening. An increase in primarily
elevated convection is expected from mid/late evening onward, in
response to a nocturnally strengthening low-level jet, and eventual
approach of the southern Rockies shortwave trough.
Increasing deep-layer flow/shear and some steepening of midlevel
lapse rates late in the period will support potential for at least
transient storm organization tonight, though guidance continues to
vary regarding the coverage and intensity of overnight elevated
convection. Isolated large hail and localized strong/damaging gusts
will be possible with the strongest storms into early Saturday
morning.
..Dean/Thornton.. 10/17/2025
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TNkGqd
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
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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)
Friday, October 17, 2025
SPC Oct 17, 2025 0600 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)




















