textproduct: Central Illinois

KEY MESSAGES

- Much warmer air will arrive Wednesday and Thursday. Near record highs in the low to mid 80s are expected on Thursday across central and southeast IL. There is a 60-80% chance of greater than 85 degrees west of I-55 and south of I-74.

- Showers and thunderstorms will accompany a cold front Thursday afternoon/night. There is a slight risk (level 2 of 5) for severe weather Thursday, with the risk for large hail, and perhaps a tornado or two.

DISCUSSION

Issued at 236 AM CDT Tue Mar 24 2026

A high pressure system will continue to gradually float eastward over the next few days. This will bring gradually increasing temperatures ahead of the next low pressure system Thursday. The warmest highs are on Thursday have a 70-90% chance of exceeding 80 degrees south of I-74 and a 60-80% chance of greater than 85 degrees west of I-55 and south of I-74, based off the NBM probabilities. We could potentially blow away the record highs for Thursday as the records are 79-82 degrees for our 3 climate sites.

Thursday's low pressure system will be accompanied with the warm front lifting north on Wednesday night and a strong cold frontal passage Thursday. The warm front could bring some showers and thunderstorms to central IL late Wednesday night into early Thursday morning. The cold front looks to bring storms, potential excessive rainfall, and a sharp drop off in temperatures again. SPC has given central IL a slight risk (level 2 of 5) for severe weather for this event, with the risk for large hail, and perhaps a tornado or two. Then environment, based off forecast soundings, looks to be primed but will have to fight a cap like Sunday evening. MUCAPE values of 1500-1800 J/kg, with 40-50 knots of bulk wind shear. The thing that stands out is the PWATs, which are around 1.3-1.5, and the long skinny CAPE profile. These storms could be efficient rain producers.

Behind the front, lows Thursday night will dip down into the mid 30s to low 40s. Highs on Friday won't be much warmer, with values in the upper 40s nearing 50. As of now, there is a 60-90% chance that temperatures will get back above 70 degrees by next Monday west of I- 57.

The Climate Prediction Center 8-14 Day outlook has 70-80% chance of above normal temperatures over IL with precipitation trending 40-50% chance above normal. So the mild and wet/unsettled pattern looks to continue at least into early April.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 556 AM CDT Tue Mar 24 2026

VFR conditions expected the next 24 hours, with periodic ceilings in the 10kft range or higher. Southeasterly winds generally 10 knots or less will persist through the 12z period.

CLIMATE

Issued at 100 PM CDT Mon Mar 23 2026

Records Highs on Thu/Mar 26...

Charleston.... 84 in 1907 Danville...... 78 in 2007 Galesburg..... 83 in 1991 Lincoln....... 79 in 2007 Normal........ 83 in 2007 Olney......... 85 in 1907 Peoria........ 82 in 1907 and 1991 Springfield... 81 in 1991 Urbana........ 81 in 1907

ILX WATCHES/WARNINGS/ADVISORIES

None.