textproduct: Central Illinois

KEY MESSAGES

- A large winter storm will likely bring 2-4 more inches of snow to areas from I-55 east this morning and early afternoon, with 4-6 more inches in southeast IL where 4-8 inches has already fallen since midday Saturday. A Winter Storm Warning from Cass to Vermilion counties southward through 6 pm today. A Winter Weather Advisory north of these counties until 3 pm, except until noon for Knox and Stark counties.

- Northerly winds gusting 20 to 30 mph today especially east of the IL river will lead to some blowing and drifting snow, especially on east-west oriented roads and in open rural areas.

- Frigid temperatures will likely continue through at least next weekend across central and southeast IL. Wind Chills will lower back down to 15-25 below zero across the area overnight into Monday morning. An Extreme Cold Warning has been issued east of I-55 with a Cold Weather Advisory from Sangamon, Logan and McLean counties west. Additional Cold Weather Advisories may be needed overnight Monday night, Tuesday night and Wed night especially east of the IL river where wind chills likely lower to 10-20 below zero.

DISCUSSION

Issued at 400 AM CST Sun Jan 25 2026

Radar mosaic shows a large area of light snow over IL with northeast moving bands of moderate to heavy snows in southeast IL where vsbys have been down to 1/4-1/2 mile for several hours se of I-70. Between 1-4 inches of snow common over central IL with 4-8 inches in southeast IL so far. Oblong in Jasper county reported 8 inches of snow at 230 am. Seeing between half and 1 inch snowfall rates per hour in southeast IL with the 1 inch rates with vsbys 1/4 mile from Robinson to Olney southeast into Lawrence county. Strong frontogenetic forcing from 500-700 mb over southeast IL goes through 12Z/6 am and then weakens. So a few more hours of moderate to heavy snowfall in southeast IL where another 4-6 inches of snow expected this morning. A few spots in southeast IL could see over a foot of total snowfall by mid afternoon. The latest CAMs show most of the light to moderate snows shifting east of the IL river after sunrise this morning and then diminish from west to east during the afternoon. Have the winter wx advisory ending at noon over Knox and Stark counties and at 3 pm for rest of the winter wx advisory further southeast. The Winter storm warning now ends at 6 pm, and likely will be able to cancel a few hours early over western part of warning area. NNW winds to increase to breezier levels during this morning with gusts 20-30 mph today especially east of the IL river where blowing and drifting snow to be more common today.

1008 mb low pressure over south central mid TN has a frontal boundary/surface trof extending ne into southeast KY and WV, with deep Gulf moisture flowing into this winter storm system. The mixed pcpn of sleet and freezing rain is staying southeast of IL. Arctic high pressure lurking to our north across the Great Lakes with NNE winds keeping very cold temps over the area with readings of 4-9F in central IL and lower teens se of I-70. Wind chills were 7-14 below zero in central IL and zero to 5 below in southeast IL. Highs today only 12-16F with wind chills in the single digits below zero, even at 10-14 below into mid morning in central IL.

Clouds to decrease from the west during tonight and bitter cold lows in the single digits below zero return. Wind chills to lower to 15-25 below zero overnight into Monday morning and have issue extreme cold warning se of I-55 and continue the cold air advisory from Sangamon, Logan and McLean counties west. McLean county will be close to the 25 below criteria for extreme cold warning and may need to be upgraded.

A strong 1040 mb Arctic high pressure over southern Saskatchewan to settle into the Southern Plains on Monday and ridge into IL. Partly to mostly sunny skies but very cold Monday with highs 7-12F with brisk WNW winds giving wind chills in the single digits to around 10 below zero yet on Mon afternoon. Lows Mon night range from zero to 5 below east of I-55 and zero to 5 above west. Wind chills likely lower to 10-20 below zero east of the IL river overnight Monday night and another Cold Weather Advisory may be needed over portions of central/eastern CWA. A northern stream clipper system passing north of the Great Lakes by Tue morning to push a cold front dry through central IL Tue morning and will see brisk SW winds early Tue switching NW behind the cold front during late Tue morning and Tue afternoon.

Another clipper system tracking a bit further south into the Great Lakes region Wed could bring light snow chances into parts of central IL on Wed afternoon. IL to remain in a Northwest upper level flow during rest of the week and could see more clipper system passing nearby and bringing reinforcements of colder Canadian air into the region. The frigid temps look to continue at least through next weekend with highs staying well below freezing. We may also need additional cold weather advisories for overnight Tue night into mid Wed morning and overnight Wed night into mid Thu morning especially east of the IL river where wind chills likely lower to 10-20 below zero. We will likely end January with below normal temperatures across the area despite the very mild weather we had during the first half of the month.

CPC 8-14 Day Outlook for Feb 1-7th has 35-45% chance of below normal temperatures over central and southeast IL, with temps trending near normal in northwest IL. There is a 45-50% chance of below normal precipitation over central/se IL during the 1st week of February.

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AVIATION

(For the 12z TAFs through 12z Monday Morning) Issued at 516 AM CST Sun Jan 25 2026

Light snow with IFR to MVFR visibility and MVFR ceilings currently ongoing across all central IL terminals this morning. This will continue for several hours, then improve from west to east this afternoon as snow ends and ceilings rise. NNE winds currently will back north midday then northwest later this afternoon. Gusts to around 25 kt will be common today with gusts decreasing after sunset.

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ILX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until noon CST today for ILZ027-028.

Cold Weather Advisory from midnight tonight to noon CST Monday for ILZ027>031-036>038-040>042-047>051.

Winter Weather Advisory until 3 PM CST this afternoon for ILZ029>031-036>038-040-041.

Winter Storm Warning until 6 PM CST this evening for ILZ042>057- 061>063-066>068-071>073.

Extreme Cold Warning from midnight tonight to noon CST Monday for ILZ043>046-052>057-061>063-066>068-071>073.