textproduct: Central Illinois

KEY MESSAGES

- A 20% chance of thunderstorms exists across east-central IL from 3-8 pm today. While severe storms are unlikely, a strong storm or two cannot be ruled out.

DISCUSSION

Issued at 210 AM CDT Sat Aug 22 2026

The early morning storms will continue to dissipate as they push southeast across central Illinois. What's left of the storms should be near to south of I-70 by 4 am. The weak cold front will shift winds to the northwest early this morning...ushering in slightly cooler temps. Temps will rebound into the 80-85 degree range for today. We'll see lower 500 mb heights for the weekend into Monday as an upper trough passes through the Great Lakes region...keeping temps a few degrees below normal. Sunday and Monday look to have highs in the upper 70s to low 80s. Regarding shower/storm chances today, the HREF mean has 1000-2000 J/kg of CAPE across central IL by midday... with some models teasing of a line of convection extending east to west from Danville to Lincoln by 5 pm. Have introduced some slight chances of storms moving south from 3 pm to 8 pm across east- central IL. SPC just has general thunder in this area...severe storms are not expected. PWATs are rather low, 1-1.25 inches, favoring a rather isolated storm setup. With 30kts of deep shear and some upper support, a strong to near- severe storm can't be ruled out, despite the drier air. Tonight, much drier air aloft will push into the area, bringing clearing skies and allowing lows to drop to the upper 50s to low 60s.

For the work week, expect cooler than average temperatures at the front of the week give way to near normal temps for the mid to latter part of the week. We'll see another upper trough move from the Northern Plains into the Great Lakes region for Wed- Thu. Precipitation looks rather limited due to the pattern. However, there could be some low chances showing up as we get closer to the Wed-Fri timeframe. Models are hinting at something more organized for the latter part of next weekend. We'll see if this gains traction in upcoming model runs.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 611 AM CDT Sat Aug 22 2026

A cold front has pushed across central Illinois leaving a modest NW breeze in its wake. Winds will pick up into the 10-12kt range during the afternoon, then drop off below 10 kt after sunset this evening. VFR conditions and dry weather are expected to prevail through the day, though there is an off chance (20%) for a stray shower or storm this afternoon, especially across east central Illinois.

ILX WATCHES/WARNINGS/ADVISORIES

None.