textproduct: Central Illinois

KEY MESSAGES

- Scattered snow showers may produce up a half to 1 inch in spots, with some areas seeing little or no accumulation. Brief snow squalls, especially during the late afternoon and evening commute, could cause localized visibility drops and slick travel.

- Dangerous cold is the main concern: A persistent cold pattern will bring single digit lows and below zero wind chills Saturday night through Tuesday morning, with only a chance of light snow showers or flurries this weekend, mainly during the afternoon hours.

DISCUSSION

Issued at 200 PM CST Fri Jan 16 2026

The 20Z/2 pm surface map shows 995 mb low pressure over central upper MI with an arctic cold front extending through central WI into eastern Iowa. A strong 516 decameter 500 mb low was spinning over central upper MI and another strong 518 decameter 500 mb low over northern MN. A deepening mid/upper level trof was over the Midwest with a strong short wave over the eastern Dakotas. Radar mosaic shows isolated to scattered snow showers (possibly mixed with light rain) recently developing along and nw of the IL river, but were more numerous further west of IL over Iowa and central and western MO. Also a band of light rain/snow was over far southeast IL, affecting mainly se part of Lawrence county with light snow at the Mt Carmel airport. Breezy west to SW winds gusting 20-30 mph brought in milder upper 30s/lower 40s early this afternoon over the CWA, except mid 30s in Lawrence county.

The arctic cold front is forecast to track southeast toward I-55 around or just after 00Z/6 pm and pass through much of central IL during this evening, getting thru southeast IL early overnight. . The latest CAM runs continue to show isolated to scattered snow showers moving eastward from the IL river valley over rest of central IL by sunset and into southeast IL early evening. The snow squall parameters by SPC show an uptick in parameters between 23Z-02Z from I-72 north. The best instability continues to be over sw CWA late afternoon and early evening, mainly after sunset and weakens during mid/late evening. Have increase chances of snow showers to 30-50% during late afternoon and evening over much of CWA. Mainly just a dusting over most areas but a few spots could see a quick half to 1 inch of snow in heavier snow burst along with reduced vsbys below a mile and wind gusts of 30-40 mph. Snow showers become more isolated and lighter overnight. Colder lows tonight in the mid to upper teens in central IL and lower 20s in southeast IL.

The very strong mid/upper level trof to dig into IL during Saturday afternoon/evening and we will likely see more isolated to scattered light snow showers/flurries during the afternoon hours especially north of I-70. Blustery west to WNW winds gusting 20-30 mph along with mostly cloudy skies will not allow much temperature rise. Highs Sat in the low to mid 20s, ranging from upper teens in Knox and Stark counties to the upper 20s se of I-70. Lows Sat night range from 8-13F with wind chills getting down to zero to 6 below north of I-70. Yet another upper level trof digs into IL Sunday afternoon and increases clouds and could bring more isolated light snow showers and flurries. SW breezes Sunday with highs in the mid to upper 20s. Another arctic cold front pushes se through central IL during Sunday night reinforcing the polar air mass. Lows Sunday night in the single digits in central IL and lower teens in southeast IL. Wind chills of 10-18 below zero overnight Sunday night into Monday morning north of I-70 and may need a cold weather advisory then. Brisk nw winds continue on Monday with more sunshine, but very cold highs in the teens except near 20F south of I-70. Bitter cold temps continue Mon night with lows in the single digits and wind chills in the single digits below zero as west to NW winds gradually subside.

High pressure moves into the TN and lower MS river valley on Tue with sw breezes developing over IL and nudging temps back up closer to freezing, with highs in the upper 20s to around 30F. Lows Tue night mostly in the lower 20s. Much milder temperatures return Wed with highs in the upper 30s to mid 40s, mildest in southeast IL as dry weather continues as low pressure passes by north of IL over the Great Lakes. The extended models have trended further south with southern stream wx system next Thu/Fri as the ECMWF was showing with yesterdays runs. We may actually be affect by northern stream system passing from the northern plains into the Great lakes and if pcpn occurs is could be a mix.

The Climate Prediction Center (CPC) 8-14 Day outlook for Jan 21-29th has a 40-50% chance of below normal temperatures and a 40-45% chance of above normal precipitation. So the rather active and colder weather looks looks likely to continue the next two weeks over central and southeast IL.

07

AVIATION

(For the 00z TAFs through 00z Saturday Evening) Issued at 500 PM CST Fri Jan 16 2026

Scattered snow showers are ongoing and will continue through the first several hours of the period. The greatest coverage is near KSPI, and this will spread east towards KDEC towards 01-02z. Brief but sharp visby reductions and a dusting of snow are possible with any showers. Shower coverage should diminish after 04-06z, and while additional light snow can't be ruled out overnight the coverage was too low to include in the TAF. Winds will predominantly be out of the WNW, with gusts to 20 knots. This evening, the strongest showers could gust as high as 30-35 knots. Another round of light snow could push in from the north late Saturday afternoon/early Saturday evening, for now only mentioned this in the KPIA TAF. Ceilings will generally be between 3-4 kft during the period, but may occasionally drop into the 2-3 kft range, especially during any snow showers.

Erwin

ILX WATCHES/WARNINGS/ADVISORIES

None.