textproduct: Chicago

KEY MESSAGES

- Chance of showers Saturday night/Sunday morning east of I-55.

- Active pattern next week with showers and possible thunderstorms, then turning colder into next weekend.

DISCUSSION

Issued at 213 PM CDT Fri Oct 9 2026

Widely scattered showers are moving across parts of northern IL early this afternoon. These showers have largely formed along an elevated baroclinic zone on the leading edge of a warm advective push. The highest concentration of showers is found near and north of I-90 as they approach the Fox Valley as of 2 PM. Highest coverage is expected to continue across our far north and into southern WI through the remainder of the afternoon with generally lesser coverage farther south, but most of the Chicago metro is in for at least a brief round of light rain before the end of the afternoon. There were previously some embedded storms as these showers moved across northwest IL, but lightning coverage has since retreated up into southern WI and thunder chances locally through the afternoon will be low, highest near the WI state line. One exception is a persistent narrow corridor of showers and embedded thunderstorms that has been stirring near our southwestern CWA border for a couple of hours along a defined confluence axis. This feature is expected to make little headway toward the northeast into parts of Livingston and LaSalle counties as it gradually fizzles away through mid-afternoon.

The area should be rain-free for the evening and mostly cloudy skies will clear out to the east. Temperatures are expected to drop into the 50s by early tomorrow and stay closer to 60 in and around the city. Though we'll be parked beneath a stout nocturnal inversion, a low level jet just off the deck with as many as 30 to 35 kt of flow at 975 mb should bring marginally breezy conditions overnight with occasional gusts north of 20 mph possible. High-level cloud cover is expected to fill in from the southeast beginning tonight ahead of the remnant hurricane.

No precip is anticipated tomorrow, but cloud cover will continue to expand around the area through the day. Tomorrow will be a warm one with highs in the upper 70s and lower 80s and a southerly breeze. Temperatures on Sunday will range from the lower 70s in our east with thicker cloud cover and a chance for light rain to the upper 70s out west toward I-39. Light showers will be possible Saturday night and Sunday morning primarily east of I-55, although an isolated shower can't be ruled out as far northwest as I-55 and up into the city.

A broad center of low pressure is favored to track nearby and drag a cold front across the region early next week. Accordingly, we find a chance for scattered showers and embedded thunderstorms from Monday evening into early Tuesday. Warm advection ahead of the system is expected to bring more unseasonably warm temperatures to Monday with highs forecast in the 80s area-wide, including upper 80s possible across the outlying areas. More seasonable conditions are then favored through the rest of the work week. Additional rounds of precip are expected in the Wednesday through Friday window with a series of disturbances progged to move across the region.

Doom

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 647 PM CDT Fri Oct 9 2026

Light southeast winds tonight will become more southerly and increase a bit by mid-late morning Saturday. A few gusts to near 20kt are possible, but the extensive high level cloudiness from the remnants of Hurricane Isaias will probably keep gustiness more the exception than than the rule tomorrow.

- Izzi

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...None.