textproduct: Central Illinois

KEY MESSAGES

- Conditions are expected to be drier than normal for mid-May, with weekly rainfall likely totaling less than one inch.

- A warming trend will bring weekly temperatures above seasonal averages. Daytime highs are forecast to surge well into the 80s by the end of the week.

- Blowing dust is a concern for Tuesday and Wednesday, particularly north of I-70 and east of the Illinois River. Wind gusts exceeding 30 mph are likely (50-80%) during this time. Given relatively dry soils and peak farming activity, visibility along major roadways may become notably impacted due to blowing dust.

DISCUSSION

(through next Monday) Issued at 243 PM CDT Mon May 11 2026

Clear and calm conditions are set to continue through the overnight hours as a surface high and its accompanying upper- level ridge migrate across the Great Lakes region. Under mostly clear skies, temperatures are expected to drop into the middle 40s by early morning.

On Tuesday, a significant surge of low-level warm advection originating from the Plains will push into the Midwest, leading to an increase in both temperatures and dewpoints preceding a cold front. Current multi-model and ensemble forecasts indicate a 60-80% chance of precipitation by Tuesday evening. Based on the Grand Ensemble and NBM interquartile QPF, rainfall amounts are expected to be light, typically falling between a few hundredths and 0.25 inches. Although residual capping keeps the severe weather risk low--suggesting any convection may remain elevated--isolated storms could produce locally heavier rain totals.

The primary concern through the middle of the week continues to be the potential for blowing dust. Model sounding analysis suggests deep boundary layer mixing capable of producing wind gusts over 30 mph on Tuesday and Wednesday. This is supported by probabilistic data from the NBM, EPS, and GEFS, which show a 50% or higher chance for these gusts north of I-70 and east of the Illinois River. These elevated winds will likely overlap with dry soil conditions and peak agricultural activity. Because the rain forecast for Tuesday evening may not be enough to adequately dampen the soil, notable visibility drops along regional roads could occur again on Wednesday. Forecasters are monitoring these trends for possible Blowing Dust Advisory issuance.

As surface high pressure and an upper-level ridge settle over the region, dry weather is forecast to return starting Wednesday and persist through at least early Friday. With this pattern becoming established, a shift toward significantly warmer conditions is anticipated beginning Friday, as afternoon highs climb well into the 80s for the rest of the week.

From Friday into early next week, medium-range models suggest a significant influx of Gulf moisture will bring a warmer and increasingly humid airmass to the Midwest. This shift in the regional pattern may lead to more frequent convection, with thermodynamic and kinematic profiles potentially supporting severe weather across the Mid-Mississippi and Lower Ohio River valleys each day through Monday.

In addition to the warming trend, strengthening southerly winds could revive concerns for blowing dust in parts of central Illinois over the weekend. The eventual impact on visibility, however, will be contingent upon the timing and accumulation of any precipitation received during the latter half of the week.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1207 PM CDT Mon May 11 2026

VFR conditions will persist through this TAF cycle as a ridge of high pressure pushes across the regional terminals. Surface winds will be from the north this afternoon before going light and variable this evening; ultimately veering around to the south by Tuesday morning. Otherwise, look for high clouds to increase by late in the TAF period as a frontal system approaches from the north Tuesday afternoon.

ILX WATCHES/WARNINGS/ADVISORIES

None.