textproduct: Central Illinois

KEY MESSAGES

- After above normal temperatures today and Tuesday, a typical January chill is anticipated Wednesday through at least early next week.

- A cold front will bring windy and sharply colder conditions with a few rain and snow showers on Wednesday. Occasional snow showers will also be observed Thursday night through Saturday as a prominent upper trough dominates the weather across the Midwest.

LONG TERM

(Wednesday through Sunday) Issued at 342 AM CST Mon Jan 12 2026

A short-wave trough noted on 09z/3am water vapor imagery coming onshore across northern British Columbia will crest the Rockies, then dive southeastward into the prevailing upper trough over the Upper Midwest/Great Lakes by the middle of the week. This feature will help carve a significant trough further south to the Gulf Coast and send a strong cold front through central Illinois on Wednesday. Temperatures will initially be in the middle to upper 30s Wednesday morning, but strong N/NW winds behind the departing front will drop readings into the upper 20s/lower 30s by afternoon. The 00z LREF indicates a very high probability (90-100% chance) of wind gusts exceeding 30mph...and a non-zero (5-15% chance) of gusts over 40mph. The strong winds combined with the falling temps will create wind-chill values in the teens by late afternoon. In addition, a few rain and snow showers will be possible, although any precipitation that occurs will be quite light with little or no snow accumulation anticipated. A cold and windy night will unfold Wednesday night as lows drop into the teens. Despite a return to mostly sunny skies on Thursday, highs will remain in the 20s.

After that, additional short-wave energy will drop southward out of Canada...re-enforcing the dominant upper trough in place over the eastern CONUS. This will ensure a cold January weekend with highs struggling to reach the lower to middle 20s and overnight lows dipping into the single digits. In addition, occasional snow showers will occur Thursday night through Saturday as the waves drop into the region. While no major storm systems will impact the region, a light snow accumulation will be likely during that period.

Barnes

AVIATION

(For the 12z TAFs through 12z Tuesday Morning) Issued at 539 AM CST Mon Jan 12 2026

VFR conditions will prevail through the entire 12z TAF period. An area of mid/high clouds currently over Iowa will spill into central Illinois this morning through early afternoon. Skies will become BKN-OVC with ceilings as low as 15,000ft. Once the cloud area shifts into Indiana, only SCT high clouds are anticipated tonight through early Tuesday morning. Winds will be SW at 10-15kt...with gusts exceeding 20kt along/east of I-55 today. The winds will decrease to less than 10kt by sunset.

Barnes

ILX WATCHES/WARNINGS/ADVISORIES

None.