textproduct: Central Illinois

KEY MESSAGES

- After highs in the 50s today, sharply colder conditions with readings falling into the 20s are expected by Wednesday afternoon.

- Another surge of very cold air will arrive by the weekend. Highs will only reach the teens and 20s while overnight lows dip into the single digits both Saturday and Sunday.

- No major storm systems will impact central Illinois through early next week: however, occasional snow showers Thursday night into Saturday may result in a minor snow accumulation.

LONG TERM

(Thursday through Monday) Issued at 331 AM CST Tue Jan 13 2026

High pressure will build into the region for Thursday, providing mostly sunny and cold conditions with highs in the 20s. As the high shifts eastward into the Ohio River Valley, the next in a series of short-wave troughs will quickly approach from the northwest by Thursday night. The trough will enhance WAA on the back side of the departing high and will trigger a band of light snow that will likely lead to a minor accumulation by Friday morning. While this will not be a significant snow event and it is still too early to pinpoint exact amounts, the 00z LREF indicates a 30-50% chance of greater than 1 inch of snow along and north of a Macomb to Tuscola line Thursday night into Friday morning. The snow will taper off and may come to an end by midday Friday as the strongest lift shifts east of the region. In addition, surface temperatures warming back into the upper 30s to around 40 degrees will lead to melting of any snow that manages to accumulate.

Yet another short-wave trough is progged to dive southward out of Canada...further sharpening the prevailing upper trough east of the Rockies this weekend. As it arrives, it will help pull another surge of even colder air into Illinois. A few snow showers will accompany this features on Saturday: however, the main weather story will be the cold. Highs will drop into the 20s on Saturday and into the teens and lower 20s by Sunday...while overnight lows plunge into the single digits. While some moderation in temperature is expected by early next week, teleconnections and medium range computer guidance suggest below normal temperatures will linger through the end of the month.

Barnes

AVIATION

(For the 12z TAFs through 12z Wednesday Morning) Issued at 448 AM CST Tue Jan 13 2026

VFR conditions will prevail through this evening before MVFR ceilings arrive late tonight into Wednesday morning. Ample high cloud cover will stream across the sky this morning, with pockets of mid-level ceilings between 8,000 and 10,000ft at both KPIA and KBMI. Forecast soundings indicate the cloud cover will thicken this afternoon, but will remain VFR until a cold front passes later tonight. Based on the latest HRRR/RAP timing, have lowered ceilings to MVFR at KPIA by 07z...then further south to KDEC/KSPI by 09z. SW winds will increase and gust 20-26kt through early afternoon before slowly veering to W and decreasing to around 10kt toward sunset. Winds will then veer to NW and increase to 10-15k after FROPA overnight.

Barnes

ILX WATCHES/WARNINGS/ADVISORIES

None.