textproduct: Central Illinois

KEY MESSAGES

- Periods of showers and a few thunderstorms are expected through Friday night, with the focus gradually shifting from the I-74 corridor tonight, to near and south of I-72 for Friday and Friday night. Rainfall amounts will be heaviest near and south of I-70, Probabilities of receiving more than a half inch of rain are highest south of I-70 (60-70%).

- While a temporary warmup takes place on Saturday, it will be more toward the middle of next week before we get a sustained warming trend.

DISCUSSION

Issued at 200 PM CDT Thu May 7 2026

Short Term (through Friday night):

Latest water vapor imagery shows a shortwave pushing across Wisconsin and Illinois. Rain showers have been moving across the northern third of the forecast area early this afternoon. While lightning has been fairly minimal thus far, a 43 mph wind gust was noted at Peoria earlier as one of the showers went by. Forecast soundings keep an inverted-V signature for a few more hours, suggesting some additional stronger gusts mixing down at times. With a weak surface boundary lingering through the night, rain chances have been extended past midnight, concentrating on the I-74 corridor.

Another shortwave will shift eastward out of the northern and central Plains on Friday. With the surface boundary only making modest progress southward, the rain focus will be more across areas near and south of I-72/Danville. A few hundred joules of SBCAPE should support a little more in the way of thunder. It looks to take well into the night for the rain to clear the southeast CWA, once the shortwave finally arrives. Further north, a drying trend north of I-74 should be taking place as early as mid-late afternoon, gradually ending from northwest to southeast.

Long Term (Saturday through Thursday):

The persistent troughing over the eastern U.S. finally begins a more wholesale shift eastward early next week, as the western upper ridge tries to build eastward. Synoptic models slide another shortwave down the top of the ridge, moving into the upper Mississippi Valley on Tuesday. While there are some differences amongst the models in the strength of this system, they are in decent agreement with the next significant rain chances in the the Tuesday/Tuesday night time frame. Beyond that, the ridge flattens a bit, but the air mass trends more toward one of the Pacific origin. This should get us toward more typical mid May temperatures later next week, which looks to persist into the following week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1218 AM CDT Fri May 8 2026

Periods of showers and storms are expected through the TAF duration with the highest chances Friday afternoon into early evening. Predominantly VFR conditions are forecast though brief MVFR cig/visby reductions are possible with any thunderstorms. Light and variable winds overnight will increase from the southwest by mid morning, then lessen once again Friday night.

ILX WATCHES/WARNINGS/ADVISORIES

None.