textproduct: Central Illinois

KEY MESSAGES

- Breezy through late this afternoon with southwesterly winds gusting 30-40 mph.

- A gradual warming trend continues late this week. By Saturday, there is a high chance (75-90%) of temperatures reaching the 70s.

DISCUSSION

Issued at 120 PM CST Tue Nov 11 2025

The primary concern for this afternoon is gusty winds and dry conditions, which could lead to unwanted spread of fire in locations that did not see accumulating snow yesterday morning. MSLP gradient has tightened ahead of a surface trough, which is currently passing through central IA. Latest METARs show 30-40 mph southwest wind gusts common. This has mixed down low dewpoints, resulting in RH around 30-35%, despite cool temperatures in the upper 30s to lower 40s. By early evening the low-level jet decouples, and winds will subside. High clouds will thin and set the stage for a cool night, though warmer than the past few, in the low-mid 30s.

Mid level heights gradually rise for the last half of the week, due to amplifying ridging over the central CONUS. Deterministic GFS and ECMWF are in strong agreement on warm air advection through the period. This will lead to a increase in temperatures back above normal. Highs on Wednesday are likely to reach the mid 50s to near 60F, with Thursday being a few degrees warmer. A period of lighter winds is expected on Thursday when a surface ridge slides south of the Ohio Valley.

Anomalous/near record breaking warmth will expand over the region Fri-Sat. Stronger southerly flow develops ahead of a deep trough digging into the western CONUS. The IPS and GEFS means show 850-mb temperatures reaching 13-17 C, which is near the 99th percentile for mid- November. This supports high confidence for NBM's advertised temperatures reaching the mid-70s on Saturday. Gusty southwest winds reaching 20-30 mph will accompany the warmth.

12z ensemble solutions show a quicker progression of a cold front this weekend, now crossing the region late Saturday or early Sunday. With upper dynamics displaced well to our north, and ridging along the Gulf Coast, prospects for rain are quite low. This is reflected in NBM's latest PoPs reduced to slight chance through Sunday. A return to cooler, more seasonal temperatures is likely early next week.

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AVIATION

(For the 18z TAFs through 18z Wednesday Afternoon) Issued at 1112 AM CST Tue Nov 11 2025

Main aviation forecast concern over the next 24 hours is wind. South winds currently gusting near 30 kt will veer southwest this afternoon with the approach of a weak surface trough. Gusts to diminish around sunset with continued backing west as the trough passes through. A few hours of marginal LLWS are possible at KCMI- KDEC this evening due to a low level jet passing through the lower Ohio Valley. Gusts will again increase late Wed morning near 20 kt from the west-northwest. VFR trough the forecast with only high clouds forecast.

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ILX WATCHES/WARNINGS/ADVISORIES

None.