textproduct: Central Illinois

KEY MESSAGES

- A risk for damaging wind gusts will persist along and north of the I-72 corridor through 2am.

- While thunderstorms will weaken below severe limits after 2am, training cells will lead to a Marginal Risk (5-15% chance) of mainly urban flash flooding along and south of I-72 through daybreak.

- A strong cold front will bring a return to winter-like conditions early next week. There is an 80-100% chance of low temperatures dropping into the teens by Monday night.

LONG TERM

(Friday through Tuesday) Issued at 113 AM CDT Wed Mar 11 2026

Low pressure will track through the Northern Plains/Upper Midwest Thursday night...perhaps triggering a few showers as far south as the I-74 corridor. Once the low passes, a return to mild and dry conditions with highs in the middle to upper 50s is anticipated for Friday. After another dry day on Saturday, a stronger and more southerly tracking low will move into the Midwest on Sunday. While there are still some timing/track differences among the models, the 00z Mar 11 GFS shows MUCAPEs of 200-300J/kg and 0-6km bulk shear increasing to greater than 60kt by Sunday afternoon. As a result, the Colorado State machine learning algorithm indicates a 5-15% chance for severe weather. Current forecast includes showers and a slight chance for thunder late Saturday night into Sunday, but the thunder chances may need to be increased if trends continue.

Once the Sunday system passes, deep-layer northwesterly flow will bring a chunk of very cold Canadian air southward into the Midwest early next week. GFS 850mb temps drop into the -10 to -15C range by Monday, supporting high temperatures in the lower to middle 30s. The coldest readings will arrive by Monday night as high pressure leads to excellent radiational cooling conditions. The 00z NBM suggests a high probability (80-100% chance) of low temperatures dipping into the teens by early Tuesday morning.

Barnes

AVIATION

(For the 12z TAFs through 12z Thursday Morning) Issued at 554 AM CDT Wed Mar 11 2026

A messy start to the period, with widespread showers, departing storms, and a front progressing from northwest to southeast. IFR ceilings are likely for a few hours behind the front. Rain lingers at the terminals this morning, then after a brief lull another round of showers pushes in from the west late this morning. A few embedded thunderstorms could impact KSPI/KDEC between 15-19z. Winds turn from west- southwesterly to northwesterly, with gusts of 20-25 kts becoming common behind the front. Ceilings should lift to MVFR by the afternoon, then VFR by the evening. Winds gradually weaken into the overnight hours.

Erwin

ILX WATCHES/WARNINGS/ADVISORIES

None.