textproduct: Central Illinois

KEY MESSAGES

- More seasonable temperatures in place for the next week, highs in the 80s and lows in the 60s.

- A cutoff low moving near IL late this week, will likely bring periods of showers and a few thunderstorms Friday into this weekend. Severe weather looks unlikely.

DISCUSSION

Issued at 141 PM CDT Tue Jul 28 2026

We have entered into a period of much more seasonable temperatures and less humid conditions. The rest of this week into the new week will have highs in the 80s and lows in the 60s. This more seasonable pattern may not last long as the CPC has above normal temperatures for the days 6-10 and 8-14 outlooks.

Wildfire smoke from the fires out west in Oregon and Washington is riding the ridge. Skies where there aren't clouds will appear hazy from the smoke. The smoke should remain elevated and not come down to the surface. Main effects we will see are vibrant sunrises and sunsets where skies are clearer, so get those cameras ready!

The forecast will be dry in terms of precipitation for the next few days as ridging remains in place off to our west. Moving into Friday, the ridging begins to get disturbed as upper wave and surface low pressure moves across the Plains into the Midwest. High PWATs return the Illinois as this wave of showers and thunderstorms makes the journey across the region. These showers and thunderstorms could be proficient rain producers. The current QPF for Friday through Saturday is showing 1-2.5 inches of rainfall, mainly north of I-70, with lesser amounts south of I-70. WPC has a slight risk of excessive rainfall for western IL and a marginal risk for eastern IL. It does look like the severe risk with this system is low. MUCAPE values are only a couple hundred J/kg, but bulk shear values are decent. The machine learning models are depicting a lowered to no severe threat late this week. Rain chances continue into the new week next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1220 PM CDT Tue Jul 28 2026

VFR conditions are expected to prevail through the 18z period for all sites except CMI. CMI is being impacted by a lower cloud deck that is being advected from Lake Michigan. The skies should begin to clear or at least become VFR at CMI by this evening. Winds from the north today around 10-15 knots this afternoon. This evening, winds will become light and variable but generally out of the north.

ILX WATCHES/WARNINGS/ADVISORIES

None.