textproduct: Central Illinois

KEY MESSAGES

- Winds blowing out of the northwest will gradually ease through the afternoon. Sporadic gusts to 40 mph will linger through around noon, tapering to 30 mph by 4pm.

UPDATE

Issued at 1010 AM CST Mon Dec 29 2025

In coordination with neighboring NWS offices, we eliminated the Wind Advisory at 10am. The surface low is now located well off to our northeast across Ontario, and the pressure gradient will continue to weaken as high pressure shifts into the region in its wake. From mixing techniques via forecast soundings and raw CAM output, it appears sporadic gusts to 40 mph will continue through noon or so, tapering to 30 mph by around 4pm.

The only other change we made to the forecast this morning was the addition of PoPs to account for the snow showers observed via visibility reductions on sfc obs and "streamers" on upstream radar imagery. It's unclear whether that will hold together into our neck of the woods, but despite not being forecast by any high res model it seems to be continuing its southeastward march. Thankfully, most visibility reductions have been to 3-6 miles (and not <1), so the probability of impacts is low, especially with the wind quickly blowing it off of roadways.

Bumgardner

DISCUSSION

Issued at 131 AM CST Mon Dec 29 2025

With the big low pressure system off to our northeast, over the Great Lakes region, the worst of it has ended. All that remains is the very strong gradient winds and light flurries that are ongoing. The flurries shouldn't amount to much, with amounts around maybe a tenth or two. The winds have been doing a good job of blowing the snow off the roads, limiting the travel impacts. However, there could still be some slick spots as we go in the morning where any remain liquid or snowfall on the roads freeze to any untreated surfaces. Snow flurries will mainly be confined to north of I-72 and should end by mid morning today.

The wind will continue to roar as we move into late morning today. The wind advisory is in effect for all of the CWA through 21z (3pm). The west-northwest wind gusts will begin to die down by 18z (12pm) gradually. We have been seeing wind gusts as high as 60 mph in some localized areas. Apparent temperatures will be very cold this morning as the temperatures remain in the teens, mixing with the strong winds. We are already seeing wind chills as low as 10 below zero and they are expected to continue into late morning. By this evening, winds will be around 10-15 mph, with gusts of 20-25 mph.

Beyond today, a more winter-like pattern sets up for central and southeastern IL for the end of the year. There is a small chance (10- 20%) of a tenth of an inch of snow north of I-74 Wednesday into Thursday this week. More arctic air will try to spill southward late in the week. Highs are expected to range in the 30s Tuesday through Saturday. Overnight lows will be warmest Tuesday night in the mid 20s, but will be in the teens to low 20s the rest of the week.

Copple

AVIATION

(For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1142 AM CST Mon Dec 29 2025

As a deep low pressure system in Ontario pulls away to the northeast, the gradient will gradually relax across central IL allowing winds to ease at the terminals through tonight. Early tomorrow morning, winds, sustained around 10 kt by that time, will back to a west-southwesterly direction. Snow showers may cause brief visibility reductions into the MVFR category through mid afternoon today, but MVFR ceilings will linger longer - finally exiting west to east between 04z and 10z (10pm to 4am).

Bumgardner

ILX WATCHES/WARNINGS/ADVISORIES

None.