textproduct: Central Illinois

KEY MESSAGES

- Widespread rain will occur across central and southeast Illinois today. Amounts of 1 to 2 inches will be common. Isolated higher amounts over 3 inches could result in flash flooding.

- There is a Slight Risk (level 2 of 5) for severe weather along and south of a Jacksonville to Danville line from 2 PM to 10 PM today.

..NEXT WEEK

Lingering rain showers remain possible over eastern IL into Monday morning as the upper- level trough crosses the region. Cooler, drier air filters in on Monday afternoon on northwest winds, with highs only in the mid-70s.

Surface high pressure builds over the Midwest on Tuesday, bringing dry conditions and seasonably mild temperatures with highs in the upper 70s to lower 80s.

For the mid-to-late week period, the official forecast relies closely on NBM guidance, though confidence drops due to notable model disagreements. The main forecast periods of precip are associated a frontal passage late Wednesday, and a stronger shortwave projected over the Midwest late Friday into Saturday. Ensemble guidance show a general trend toward rising geopotential heights next weekend, suggesting warming temperatures.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 547 AM CDT Sun Jun 21 2026

A weather system will bring deteriorating aviation conditions later this morning and afternoon with lowering ceilings, RA, and embedded TSRA. We expect MVFR conditions to become widespread by early afternoon, with IFR conditions likely by evening and continuing overnight. SE winds will increase this morning and become gusty this afternoon over 20 kt. Winds will gradually back northeast at KPIA-KBMI this evening, and northwest at KSPI-KDEC- KCMI, with gusts becoming less common.

ILX WATCHES/WARNINGS/ADVISORIES

Flood Watch through late tonight for ILZ027>031-036>038- 040>057-061>063-066>068-071>073.