textproduct: Central Illinois

KEY MESSAGES

- A storm system will bring showers to central Illinois tomorrow into Thursday. The newest model data continues to back off on precipitation totals, now showing most places receiving less than one tenth of an inch.

- Below normal temperatures will arrive behind the departing storm system as highs drop into the 40s Thursday through Saturday.

DISCUSSION

Issued at 131 PM CST Tue Nov 10 2026

**** Mid-Week Rainfall *****

Two short waves are still expected to move into the region and then phase together over central Illinois and bring rain and isolated storms to the eastern part of the CWA and east of the state tomorrow and tomorrow night. The associated low pressure area that develops will track right across central Illinois tomorrow, but any precip with this system will be minimal and models continue to decrease the amount of QPF and keep most of the precip over eastern parts of the CWA. This is all due to the timing of the phasing of the two troughs over the area and that when the system depends/merges, the system will mostly be east of the state. In fact, HiRes models show no precip over western portions of the CWA. SBCAPEs are forecasted to be between 500-1000 j/kg ahead of the low tomorrow afternoon, but then the strongest dynamics with the system will be mainly east of I-57 by then. SPC Day 2 outlook as made adjustments for this with the greatest threat of strong to damaging winds being mainly in IN. However, will still include an isolated thunderstorm threat in the east in the afternoon for when the system begins it merging.

**** End of Week Cool-Down ****

As the system pushes east the 500mb trough moves in behind into Thursday and given the cold air advection expected behind the front and the dynamics associated with the trough, believe isolated to scattered showers will be possible Thursday afternoon after a bit of increase to the lapse rates. Higher pops will be possible in the east and northeast parts of the CWA as the focus shifts to lake-enhanced showers from Lake Michigan possibly clipping parts of Champaign, Vermilion, and Edgar counties. The other focus for Thursday will be the windy and much cooler conditions arriving into the area. High temperatures will only reach the middle to upper 40s across much of the region...with lower 50s south of I-70. Northwest winds gusting to 20-25mph will make it feel even cooler as wind-chill values hover in the 30s for much of the day. The coolest period will be Friday and Friday night, with highs and lows well below normal for this time of year. Highs will drop into the lower to middle 40s during the day, with lows in the lower to middle 20s. After that, the trough will shift to the east and northeast by early next week. As a result, temperatures will rise back to more seasonal levels in the mid to upper 50s for next Monday and Tuesday.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1138 AM CST Tue Nov 10 2026

VFR conditions will prevail at all TAF sites the next 24hrs with clear skies today. High broken cirrus will arrive late this evening in the north and spread into central IL late tonight. Few to scattered mid clouds will advect into the area tomorrow morning with broken lower cirrus as well. Light showers are possible tomorrow morning at PIA and BMI as a weather system begins to develop over the area. Do not think the showers will affect SPI, DEC, or CMI. Winds will be light and variable through tonight, but then become south-southwest tomorrow at less than 10kts.

ILX WATCHES/WARNINGS/ADVISORIES

None.