textproduct: Central Illinois

KEY MESSAGES

- A few brief afternoon thunderstorms are possible (30-40% chance) across central Illinois this afternoon and early evening. 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 low to mid 80s Monday and mid to upper 80s Tue/Wed.

Thursday and Friday: Unsettled Weather Returns

A stronger northern stream short wave tracking ESE over the upper Midwest/upper MS river valley Wed night and into the southern Great Lakes region Thu, to bring a frontal boundary into northern IL Thu and bring increasing chances of convection to central IL overnight Wed night and Thu. This boundary pushes south into central IL Thu night and Friday and into southern IL Fri night and Saturday. Will see higher chances of convection Thu/Fri and shifting more south on Saturday. PW values are rising back up to 2 inches late work week and supports heavy rain chances. Will see more unstable airmass return to area Thu/Fri. CSU-MLP and CIPS shows marginal risk of severe storms nw IL Wed night and over more of CWA Thu/Thu night and shifting into southern/se IL Friday into Saturday.

The Climate Prediction Center (CPC) 8-14 Day Outlook for July 13-19th has 45-55% chance of above normal temperatures over IL (highest in west central IL) and 33-40% chance of below normal precipitation. The ECMWF and GEM models are both showing a strong 500 mb high/ridge (598-600 decameters) building eastward into the Midwest July 13-15th while GFS is keeping the strong ridge further west over the Rockies during this time frame. If ECWMF and GEM models verify, an extended heat wave may return to the Midwest including IL for middle to later part of next week.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1255 PM CDT Sun Jul 5 2026

Broken cumulus clouds with MVFR ceilings possible early this afternoon to lift to VFR during mid/late afternoon. Isolated showers and thunderstorms possible in eastern IL from 20-24Z and carried VCSH at BMI, DEC and CMI with prob30 group at CMI. Latest HRRR run is showing patches of low clouds with MVFR bases moving back into parts of central and eastern IL during overnight into mid Mon morning, though not as extensive as last night and this past morning. NNW winds 5-10 kts veer NNE tonight into Monday.

ILX WATCHES/WARNINGS/ADVISORIES

None.