Key messages
- Sunny mild days and cool nights persist across central and southeast Illinois through Monday, with highs in the 70s and lows in the 40s.
- A cold front moves across the region mid next week, though rain chances look pretty slim (20% or less), with temperatures cooling a bit for late next week.
Discussion
Issued at 116 PM CDT Thu Oct 22 2026
The stretch of dry, low-impact weather will span into next week as the central U.S. remains under the influence of a blocking pattern, which is only forecast to amplify through the weekend.
The net effect will be ideal mid-autumn weather with daily highs in the 70s and overnight lows in the 40s. For those keeping score at home, these temperatures are averaging about 8 degrees warmer than what is considered normal for middle October. While not record- warmth by any means, it is nevertheless impressive.
Mid-range deterministic model guidance demonstrates strong consistency regarding the progression of the broad western trough into early next week. While successive model cycles continue to open and eject this feature northeastward through the Central Plains, the attendant cold front consistently fails to push through central Illinois. Rather, the surface low undergoes occlusion over the Canadian Prairies, causing the trailing front to stall and weaken over the Great Lakes before eventually washing out and retreating north as a warm front.
It's not until Wednesday that a strong mid-level shortwave trough pivots across the Mid-Mississippi Valley and drives a surface cold front through the Midwest and Great Lakes region, effectively breaking down our resident ridge. This could be our next best chance for scattered showers and isolated thunderstorms, though current blended (NBM) and ensemble guidance (GEFS/EPS) mute the probability at 20% or less.
Aviation /00Z Tafs Through 00Z Saturday/
Issued at 619 PM CDT Thu Oct 22 2026
A high pressure ridge aloft will bring mostly clear skies through the upcoming 24 hours, with nothing more than a few high clouds expected Friday afternoon. Winds light and variable tonight, then becoming SE 4-8 kts after 16Z.
Ilx Watches/Warnings/Advisories
None.
KEY MESSAGES...MJA DISCUSSION...MJA AVIATION...37