textproduct: Central Illinois

KEY MESSAGES

- Below normal temperatures will prevail through this weekend, with a warming trend bringing temperatures back to above normal levels by midweek.

DISCUSSION

Issued at 212 AM CST Sat Nov 14 2026

A slow moving large scale upper low over the northeast states will gradually migrate eastward over the weekend, becoming less of an influence on central IL, as low level northerly flow acquires more of a westerly component and deflects lake effect cloud cover eastward and away from east-central IL. Meanwhile, an elongated high pressure center from Missouri through the upper Midwest into Canada will build and shift southeastward, parking over central IL by late in the weekend, for very light winds and mostly clear skies. Although the high will continue to shift eastward toward the mid- Atlantic coast through the week, it looks to keep any precipitation away from central IL through at least Wednesday, if not Thursday and Friday as well as it looks to deflect the next system well into the upper Midwest and potentially prevent a late week cold front from reaching central IL. Nevertheless, a slight chance for precipitation can't be ruled out with this feature as far east as the I-55 corridor by Friday.

Temperatures will remain below normal today and Sunday as the cool air mass lingers over the area and slowly moderates. Nighttime temperatures will show less tendency for any upward trends as the clear skies and light winds promote good radiational cooling. Expect highs in the upper 40s to lower 50s today, lower to mid 50s Sunday, and generally mid 50s Monday. Lows will be mainly mid 20s tonight and Sunday night, then upper 20s to lower 30s Monday night and Tuesday night. As southerly flow develops midweek, highs should reach the mid to upper 50s Tuesday, around 60 Wednesday, and lower to mid 60s Thursday. The warming trend could continue into Friday if the cold front is unable to push through IL.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 512 AM CST Sat Nov 14 2026

VFR conditions are expected over the upcoming 24 hours as high pressure builds into the area. Lingering cloud around 4000-5000 ft AGL mainly northeast of KBMI-KDEC this morning will shift eastward out of the area by 18Z. Winds NW 3-7 kts becoming light and variable by 00Z.

ILX WATCHES/WARNINGS/ADVISORIES

None.