textproduct: Central Illinois

KEY MESSAGES

- A few brief afternoon thunderstorms are possible (30-40% chance) across central Illinois today. Severe weather is not expected, and storm activity will fade quickly after sunset.

- Dry and seasonably warm conditions return Monday through Wednesday, with afternoon temperatures peaking in the mid- to- upper 80s.

- Thunderstorms return Thursday and Friday (60% chance). Torrential downpours will bring a localized flash flooding risk and a chance of isolated damaging wind gusts.

- A dangerous period of excessive heat could re-develop across the region by the middle of next week (July 12th onward).

Saturday and Beyond: Strong Signals for High Heat

As the late-week boundary washes out, medium-range guidance is in remarkably strong agreement regarding the building of a high- amplitude subtropical ridge across the central US into the following week. While exact details on the core amplitude and positioning will change, long-range ensembles (GEFS/EPS/GEPS) consistently track an anomalous 600-mb upper-level high directly into the Corn Belt in the 7 to 10 day window (July 12-15).

If central Illinois remains on the periphery of this ridge, active northwest flow could send periodic MCS ridge-riders through the region to temper the heat. However, if the core of the ridge centers directly over the Midwest as current trends suggest, another stretch of dangerous, excessive heat will be likely for the middle of July.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 526 AM CDT Sun Jul 5 2026

A weak surface front draped over the region has resulted in patchy fog and low stratus early this morning. Slow diurnal improvement back to MVFR and eventually VFR is expected later this morning and into the afternoon. Otherwise, have maintained the PROB30 mention for isolated showers into early evening. While thunderstorms cannot be ruled out during this time, confidence and coverage remain far too low to mention TSRA.

ILX WATCHES/WARNINGS/ADVISORIES

None.