textproduct: Central Illinois

KEY MESSAGES

- Temperatures will gradually rebound Monday through Thursday, with highs in the lower 50s Monday, increasing to lower 80s by Thursday ahead of the next cold front.

- Another chance (60-80%) for showers and thunderstorms will accompany a cold front Thursday. There is at least a low severe thunderstorm risk.

DISCUSSION

Issued at 215 AM CDT Mon Mar 23 2026

Cooler temperatures welcomes us into the new work week. Today the highs will only top out in the upper 40s to low 50s, which is closer to normal for the latter half of March. A high pressure system is setting up over the Plains/Midwest today and will gradually float eastward over the next few days. This will bring some WAA into the area Tuesday, gradually increasing temperatures ahead of the next low pressure system Thursday. The highs on Thursday have a 30-70% chance of exceeding 80 degrees south of I-74 and west of I-57, based off the NBM probabilities. The probabilities increase as you move southwest towards the STL area.

Thursday's system will be accompanied with a strong cold frontal passage. It looks to bring storms, wintry precip (maybe??), excessive rainfall, and a sharp drop off in temperatures again. The machine learning models are indicating the possibility of strong to severe storms Thursday afternoon into the evening. There appears to be a similar set up as yesterday's environment for this round on Thursday. The most notable difference between the two systems is the PWATs are much higher with this next one. The forecast soundings are showing PWAT values around 1.3-1.5. Behind the storms, the rain could change over to a rain-snow mix where the temperatures get cool enough in the nighttime hours. As of now, no measurable amounts of snow are forecast and confidence in this occurring isn't high.

Behind the front, lows Thursday night will dip down into the mid 30s to low 40s. Highs on Friday won't be much warmer, with values in the upper 40s nearing 50. As of now, there is a 30-50% chance that temperatures will get back above 70 degrees by next Monday. The weekend into next week is looking to be dry.Copple

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 556 AM CDT Mon Mar 23 2026

VFR conditions reign through the 12z TAF period today. However, BMI has a stray area of MVFR clouds moving overhead right now, which should not last long, so it has been included via TEMPO group. The forecast is focused on the winds. Northerly winds (10-15 knots) will begin to veer and lessen to 5-10 knots this afternoon. Being easterly by ~04z then finishing the shift to the south by the end of the period.

ILX WATCHES/WARNINGS/ADVISORIES

None.