textproduct: Central Illinois

KEY MESSAGES

- An arctic airmass will bring bitterly cold temperatures beginning tonight. Wind chill values as cold as 10 to 30 below zero are expected through Friday morning north of I-70. Subzero wind chills will persist Friday through Tuesday mornings.

- A long duration winter storm will bring two waves of snow Saturday morning through Sunday afternoon. Locations near and south of I-72 could see at least a 50% chance of total snow amounts exceeding 5 inches with at least a 60% chance for amounts to exceed 8 inches south of I-70.

DISCUSSION

Issued at 231 PM CST Thu Jan 22 2026

Surface analysis this afternoon depicts high pressure ridging over most of Illinois with air temperatures sitting in the upper 20s to middle 30s. Temperatures drop drastically later tonight as an arctic airmass brings bitterly cold temperatures southward. Temperatures by midnight will be in the single digits over the northern third of Illinois with lows bottoming out between -10 and 10 degrees from northwest to southeast. The pressure gradient will rapidly tighten as pressure rises with the approaching high, ultimately allowing winds to gust out of the northwest between 25-30 mph overnight. The bitterly cold air paired with strong winds will send wind chills as low as -30 north of a Havana to Bloomington line through Friday morning with values of -10 to -20 south of there to I-70. Temperatures remain cold through Friday with wind chills cold enough to continue the Cold Weather Advisory north of I-70 through Saturday morning.

The arctic front drops south of here on Friday, interacting with Gulf moisture and a couple upper waves through the weekend. The result will be an expansive area of wintry precipitation expected to impact numerous states from the southern Plains to the Mid-Atlantic region. Very cold temperatures will favor snow as our primary precipitation type with snow ratios expected to be higher than our climatological normal, peaking around 15-20:1 (light, fluffy variety). The latest suite of 12Z guidance has once again shifted things slightly further north and prompted an expansion of our Winter Storm Watch to roughly the I-72 corridor.

The snow will come in two waves, being separated by a brief lull Saturday night. Subtle isentropic ascent will bring snow to the area Saturday morning into Saturday afternoon, though this will be working against dry air in the lower levels. Because of this, snow amounts will be light with amounts of only a couple inches expected. The bigger push comes early Sunday morning through Sunday afternoon as an upper wave glides along the arctic front. This paired with a coupled upper jet will bring an enhanced area of synoptic lift to the Ohio Valley region. Forecast soundings show a deep ~600 mb isothermal layer overlapping the dendritic growth zone (-10 to -20 degrees C) for several hours on Sunday morning, which is usually indicative of high snowfall rates potentially exceeding 1 inch per hour. Total snow amounts have increased with this forecast package with the heaviest snow expected south of I-70 where there is at least a 60% chance for 8 inches or more. There is at least a 50% chance for snow amounts to exceed 5 inches near/south of I-72. The bulk of the accumulating snow will come to an end late Sunday afternoon or early evening, though light precipitation may linger through the evening hours.

High pressure ridging fills in Sunday night as a deepening high settles into the southern Plains. Brisk northwest winds and a fresh snow pack will lead to dangerously cold wind chills once again Sunday night into Monday morning with readings as low as 20 below zero. Temperatures will remain colder than normal through the new week with a less than 10% chance that we warm above freezing through next weekend. Longer range guidance suggests a drier period favored early next week, with perhaps a low chance for additional snow by the middle to end of next week with a few upper shortwaves.

NMA

AVIATION

(For the 18z TAFs through 18z Friday Afternoon) Issued at 1135 AM CST Thu Jan 22 2026

As low pressure approaches from the north, a tight pressure gradient is resulting in sporadically gusty west winds which will continue through afternoon, easing after 23z. Winds will pick back up from the north-northwest after 03z as an arctic front sinks through the area; sustained speeds will generally hover around 15 kt with gusts approaching 25 kt. High resolution guidance suggests a band of low clouds will accompany the front, possibly (30-50% chance) resulting in a brief period of MVFR ceilings, with the highest chances across the northern terminals (PIA and BMI). Otherwise, expect VFR conditions throughout the forecast period.

Bumgardner

ILX WATCHES/WARNINGS/ADVISORIES

Extreme Cold Warning from 3 AM to noon CST Friday for ILZ027>031- 036>038.

Cold Weather Advisory from noon Friday to noon CST Saturday for ILZ027>031-036>038.

Cold Weather Advisory from 3 AM Friday to noon CST Saturday for ILZ040>057-061>063.

Winter Storm Watch from Saturday morning through Sunday afternoon for ILZ044>046-049>057-061>063-066>068-071>073.