textproduct: Central Illinois

KEY MESSAGES

- Well below normal temperatures will persist through Saturday night across central and southeast IL, with our fresh snow pack likely remaining in place through at least early next week. Wind chill values of 20 to 30 below zero are forecast this morning over much of central IL. An extreme cold warning is in effect until noon from Scott, Morgan, Menard, Logan and McLean counties eastward, with a Cold Weather Advisory west until noon. Wind chill values of 10 to 20 below zero are expected tonight, hence a new Cold Weather Advisory is in effect tonight from McLean, Logan and Sangamon counties east.

DISCUSSION

Issued at 325 AM CST Mon Jan 26 2026

We added Scott, Morgan, Sangamon, Logan and McLean counties into the Extreme Cold Warning this morning until noon. Areas east of these counties remain in this warning this morning. Wind chills to get down to 18-28 below zero in the warning area. Areas west of these counties continue in the Cold Weather Advisory this morning for wind chills as low as 15-25 below zero. We issued a new Cold Weather Advisory tonight from McLean, Logan and Sangamon counties eastward for wind chills of 15 to 20 below zero. Brisk SW winds develop from nw to se during tonight and could cause some blowing and drift of the fresh fluffy snow pack over central IL tonight into Tue morning, and in southeast IL overnight into Tue morning.

Strong 1036-1038 mb arctic high pressure over western KS/OK into north Texas was ridging into the upper MS river valley. Low pressure system was off the southern New England Coast that gave us our snowfall this past weekend. Stratocumulus clouds over far eastern CWA near the IN border and drifting slowly eastward. Nearly clear skies over the rest of central/se IL. Temps were in the single digits below zero over much of central IL, with single digits above zero from Danville to Effingham east. Wind chills ranged from 15-25 below zero from I-57 west and 8-15 below from Danville to Effingham east. Jacksonville wind chill was down to 30 below zero with air temp of 11 below.

Arctic high pressure ridge to settle over central Texas and ridge ne over the Ohio river valley by late today and provide more sunshine to the CWA today but frigid temps and wind chills. Highs today in the upper single digits to around 10F. Wind chills of 15-25 below zero this morning (a few spots reaching 25-30 below) to only modify to 5-10 below zero this afternoon. We currently have lows of zero to 5 below east of I-55 and zero to 7 above over the IL river valley. These lows likely reached this evening and could get colder with fresh snow cover. These cold temps combined with increasing sw winds during this evening to give bitter cold wind chills of 10-20 below zero tonight, with some modification late tonight as wind chills rise into the single digits below zero by sunrise. SW winds gusting up to 20-30 mph tonight could cause some blowing and drifting of snow, though mainly after midnight in southeast IL where gustier winds arrive later tonight. Cold front to push se through central IL during Tue morning and thru southeast IL Tue afternoon, reaching near the Ohio river by 00Z/6 pm. This front should pass through dry with more cloud cover especially ne CWA. Highs Tue in the upper teens/lower 20s central IL and mid 20s in southeast IL.

The 00Z forecast model suites are in agreement with a strong mid/upper level trof digging over the Eastern US and putting IL in a northwest upper level flow. A few northern stream clipper systems passing by to our north to mainly affect the Great Lakes Region into mid week, with best chances of light snow to be northeast of central IL, though we could have flurries at times. Another strong arctic high pressure around 1035 mb builds into the Midwest Tue night and decreases clouds and winds Tue evening. Very cold lows 5-10 below east of I-55 and around zero from the IL river west. Lowest wind chills Tue night into mid Wed morning could reach cold weather advisory criteria again from 15-20 below zero from I-55 east. Highs Wed only in the upper teens/lower 20s. Arctic high pressure ridge near IL by dawn Thu and another chunk of arctic high pressure settling down into the Midwest late this week to ensure well below normal temperatures prevailing rest of this week along with dangerous wind chills on several days this week. A very strong 522-525 decameter 500 mb low/trof digs down into IN/OH by sunset Friday and moves into the eastern TN river valley and central Appalachians on Saturday. This system may produce light snow showers as far west as central/se IL late this week though currently Blended models keep pops less than 15% thru Saturday. We may be getting close to cold weather advisory criteria each night through Fri night especially east of the IL river.

The Climate Prediction Center (CPC) 8-14 Day Outlook for Feb 2-8th has 33-40% chance of below normal temperatures over east central and southeast IL, and near normal temps from I-55 west. CPC has 45-50% chance of below normal precipitation over CWA during the 1st week of February with 50-60% chance below normal pcpn in southern IL.

07

AVIATION

(For the 06z TAFs through 06z Monday Night) Issued at 1100 PM CST Sun Jan 25 2026

VFR conditions are expected the entire 06z period. North winds around 10-15 knots will shift out of the southwest by the afternoon with gusts around 20 knots.

Copple

ILX WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until noon CST today for ILZ027>031-036- 037-040-041-047.

Extreme Cold Warning until noon CST today for ILZ038-042-048-049- 051.

Cold Weather Advisory from 6 PM this evening to 6 AM CST Tuesday for ILZ038-042>046-051>057-061>063-066>068-071>073.

Extreme Cold Warning until noon CST today for ILZ043>046-050- 052>057-061>063-066>068-071>073.