textproduct: Central Illinois

KEY MESSAGES

- Showers and a potential thunderstorm linger east of I-57 this afternoon. Severe weather is not expected.

- After a quiet weekend, the next significant risk for strong to severe thunderstorms will arrive Monday. At this time, it appears all severe hazards will be possible Monday afternoon and evening as a potent storm system lifts through the region.

UPDATE

Issued at 1027 AM CDT Fri Apr 24 2026

Showers with a threat of a few thunderstorms will continue east of I-55 into the afternoon as a cold front works its way across the area today, combined with a shortwave promoting widespread showers from southwest to east-central IL this morning. Have increased PoPs to likely category in east-central IL through mid afternoon for this feature, and decreased highs a couple of degrees in anticipation that the widespread cloud cover will limit diurnal temperature increases. Still, a relatively warm day for April is on track with highs in the lower to mid 70s.

DISCUSSION

Issued at 230 PM CDT Fri Apr 24 2026

*** Lingering showers departing, fair weather for the weekend ***

Showers and a few thunderstorms lingering east of I-57 this afternoon in the vicinity of a cold front will depart the area should depart the area to the east this evening. Skies will clear overnight with mostly clear skies expected until Sunday. Temperatures will cool from what happened the past few days, but remain above normal with highs in the mid 70s and lows in the mid 40s to 50s through Monday. Winds will slowly veer from northwesterly this evening, to northeasterly Saturday, to southeasterly Sunday, with modest wind speeds under 15 mph expected.

*** Severe thunderstorms likely Monday ***

Models have maintained good consistency with tracking a low from the southern Plains to the upper Midwest Monday, tracking a warm sector with rich moisture, dewpoints into the 60s, and fairly strong instability into central IL by Monday afternoon. 12Z GFS is already estimating around 2000 J/kg MLCAPE, while ensemble mean bulk shear of around 50 kts is forecast. Severe thunderstorms can be expected, and SPC has incorporated a 30+% risk area. Timing and mode of severe weather remain more unclear, however potential for elevated storms containing hail would be possible Monday morning north of a warm front lifting into the area, while supercells containing all severe weather hazards would be possible in the warm sector by afternoon. A cold front would potentially organize thunderstorm activity into a linear configuration by late afternoon or evening, with more widespread damaging wind, and embedded tornadoes possible.

*** Cooler weather, mostly dry through midweek ***

Behind the cold front associated with Monday's storm system, cooler air will arrive for midweek, with highs back down to the 60s, slightly below normal for this time of year. Most models are dry for central IL mid to late in the week, however a couple of potential disturbances embedded in a long wave trough over the region could clip central/southeast IL. Tuesday night PoPs are as high as 30 percent south of I-70, and Thursday to Friday PoPs reach as high as 30 to 40 percent across the area.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 634 PM CDT Fri Apr 24 2026

VFR conditional will prevail at all TAF sites next 24hrs. High cirrus will advect over the sites this evening and to the northeast, exiting around 02-04z from west to east. In the morning, some CU will develop around 5-6kft and last into the afternoon. Winds will be northwest this evening and then become more northerly and light late tonight and overnight. Winds become northeasterly 7-10kts.

ILX WATCHES/WARNINGS/ADVISORIES

None.