textproduct: Central Illinois

KEY MESSAGES

- A warming trend will gradually bring temperatures back to above normal levels over the next few days, with the mild temperatures lasting several days.

- A long stretch of dry weather is expected across central and southeast IL through at least Wednesday. This may allow the moderate to severe drought over east central and southeast IL to continue to expand further into central IL.

DISCUSSION

Issued at 202 AM CST Sun Nov 15 2026

Surface high pressure is centered nearly directly over central IL and will very slowly meander eastward over the next few days. This will bring mostly clear skies and light winds. The air mass over the region will very gradually moderate as well, with temperatures increasing a few degrees each day.

The warming trend will continue midweek as southerly flow develops behind the departing high as a low moves through the northern Plains into the upper Midwest. A cold front trailing this system looks to stall out just northwest of central IL Wednesday night into Thursday morning and brings with it a slight chance of precipitation as far southeast as the Illinois River. Otherwise, the warming trend and dry conditions should continue through Friday.

By the weekend, large model discrepancies are shown by model ensembles. There is a general theme of a stronger upper low progressing across the central U.S., but timing and track varies significantly. While various scenarios could bring little or no rainfall to central IL, a blend of model solutions results in 30-60 percent chances for precipitation between Friday night and Sunday morning. Ensembles depict moderate chances (30-60%) for a combined 100+ J/kg CAPE and 30+ kt deep layer shear with this system for the southern and central Plains, but only around 10 percent as far east as the IL River. Will need to keep an eye on the exact solution for potential inclusion of thunderstorms, but at this time chances appear too low this far east. Probabilities for storm total rainfall over an inch are only 5-15 percent across central and southeast IL, so meaningful drought reduction is unlikely. A push of colder air will likely arrive starting Sunday behind this system.

Highs should reach the lower to mid 50s today, mid 50s Monday, and upper 50s Tuesday. The warming trend will likely continue through Saturday, with highs from 65 to 70 forecast Saturday. Lows tonight should be in the upper 20s, followed by upper 20s to lower 30s Monday night.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 449 AM CST Sun Nov 15 2026

VFR skies with light/variable winds over the next 24 hours.

ILX WATCHES/WARNINGS/ADVISORIES

None.