textproduct: Central Illinois

KEY MESSAGES

- There is a Marginal Risk (level 1 of 5) for severe weather along and west of a Lincoln to Litchfield line tonight into tomorrow morning. Hazards are damaging winds and large hail.

- Periodic storm chances will persist through early next week...with the greatest probability for convection focusing on Saturday, then again late Monday into Tuesday. A marginal risk for severe weather is also in place for Friday and Saturday.

- After a couple more mild days, a preview of summer will arrive by early next week as highs soar well into the 80s by Sunday and Monday.

DISCUSSION

Issued at 256 AM CDT Thu May 14 2026

A high pressure system is set up overhead this morning. A continued gradual warm up is expected by the weekend. Highs in the upper 70s to mid 80s is forecast for the weekend into early next week. The LREF suggests Monday has the best chance of being the warmest, with 60-80% chance of highs exceeding 80 degrees.

An active period of weather is in place through the weekend into early next week. Tonight, a shortwave will pass overhead, bringing a MCS into IL. The system as a whole will be moving into a less supportive environment, so it is expected to be elevated and decaying. SPC has a marginal risk (level 1 of 5) for damaging winds and large hail in place for a line along and west of Lincoln to Litchfield. Rainfall amounts are forecast to be less than half an inch through 18z tomorrow. Timing looks like the system will enter west-central IL just after midnight tonight and will be exiting southeastern IL by mid-to-late morning.

Friday afternoon into evening may have additional showers and thunderstorms, of which could be strong to severe. Looking at a range of models, decent capping will be in place during this time, which may stunt the development of any storms. Bulk shear is quite weak (<30 knots). MUCAPE values of up to 1000 J/kg. SPC has a marginal risk (level 1 of 5) for damaging winds and large hail during this time for most of central and southeastern IL. Any storms that develop likely won't have the shear needed to survive and collapsing storms could produce damaging winds.

Saturday, another marginal risk for severe weather is in place for all of central IL and most of southeastern IL. Sufficient deep- layer shear over an unstable airmass with steep lapse rates would should support an isolated severe threat with damaging wind gusts and large hail possible.

Beyond Saturday, there looks to be the potential for more waves of severe weather into the new week. There is a 15% chance for severe weather from SPC for Monday along and west of I-55. We will continue to monitor but will need to make it through the first 3 days of severe weather before pinning anything down for Sunday-Tuesday.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1224 AM CDT Thu May 14 2026

VFR conditions continue through the TAF period. Light and variable winds underneath high pressure will continue overnight, becoming southerly during the daytime hours.

ILX WATCHES/WARNINGS/ADVISORIES

None.