textproduct: Central Illinois

KEY MESSAGES

- The stretch of warm weather is expected to last through Friday, with daily temperatures climbing near 80 degrees, and at times, the mid-80s. Breezy winds, occasionally reaching 25-35 mph, will accompany this warm period.

- This week will be riddled with thunderstorm potential. Tuesday, Wednesday, and Friday currently exhibit the highest probability (15-30%) of severe weather.

- There is also potential for substantial accumulative rainfall throughout the week, with our multi- model ensemble predicting a medium (40-60%) chance of exceeding 2 inches through Saturday in areas north of Interstate 72.

This Weekend

Thunderstorm activity is then expected to return over the weekend, specifically Friday night into Saturday. This is associated with a compact shortwave trough lifting across the Mid- Mississippi Valley ahead of a pivoting, more vigorous trough and its accompanying cold front. The CAPE/shear parameter space once again appears volatile enough to support an organized severe convective risk, even though the front appears to pass during a diurnally unfavorable time.

Following the cold frontal passage, temperatures will cool significantly from Saturday night through Monday as the warm, moist air mass from the previous week is flushed out. The latest NBM deterministic guidance supports Sunday afternoon high temperatures near 60 degrees, with overnight lows around 40 degrees. Frost potential is non-zero during this time, and will need to be monitored with subsequent updates.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 552 AM CDT Mon Apr 13 2026

A pair of low pressure systems will track across the northern Great Plains and Great Lakes, keeping central Illinois in a moderately strong southerly gradient throughout the period. MVFR ceilings are expected to become more widespread, building in from the northwest after 12Z and affecting central IL terminals through late morning, before rising above the MVFR threshold and scattering by afternoon. Southwest winds will favor a 180-220 direction and remain gusty, near 25 knots much of the time, although they will become more sporadic overnight. Due to increasing model trends, a PROB30 for TSRA has been introduced for KPIA and KBMI early this afternoon, primarily between 18Z and 22Z.

ILX WATCHES/WARNINGS/ADVISORIES

None.