textproduct: Central Illinois

KEY MESSAGES

- Snow will diminish during late this afternoon with up to an additional 1-2 inches of snow possible from highway 51 east. Winter Weather Advisory and Winter Storm Warning goes through 8 pm over central IL (excluding Clay, Richland and Lawrence counties).

- Dangerously cold wind chills are expected tonight into Sunday morning, and again Sunday night into Monday morning. The coldest wind chills will drop as low as 15 to 25 degrees below zero overnight into mid Sunday morning. A Cold Weather Advisory in effect over central and southeast IL from 8 pm this evening until noon Sunday.

DISCUSSION

Issued at 245 PM CST Sat Dec 13 2025

We are upgrading Macon county into the Winter Storm Warning until 8 pm, with snowfall amounts of 4 to 6 inches and up to another 1-2 inch of snow expected next hour or two. So McLean, DeWitt, Macon, Champaign, Vermilion, Douglas and Edgar counties have a winter storm warning until 8 pm while rest of central IL has a winter weather advisory until 8 pm (excluding Clay, Richland and Lawrence counties). Between 2-6 inches of snow has fallen over central IL since early morning. The snow was beginning to lighten up over west central IL and CAMs show the snow diminishing from west to east next few hours with most of the snow done by sunset. Areas south of an Effingham to Robinson line have limited snowfall. NNW to NW winds to gust 20-25 mph tonight and could cause some blowing and drifting snow especially in open/rural areas.

Main weather story tonight will be the bitter cold with lows in the single digits below zero and wind chills likely lowering to 15 to 25 below zero overnight into Sunday morning. We continued the cold weather advisory for CWA from 8 pm this evening until noon Sunday. Will need to monitor areas north of I-70 for possible upgrade to extreme cold warning overnight if nw winds get stronger than 10-15 mph tonight. We will likely need another cold weather advisory Sunday night into Monday morning especially north of I-70 with lows in the single digits below zero and wind chills forecast to get to 10-20 below zero. Clouds to decrease from the nw during tonight with a fair amount of sunshine Sunday but very cold highs in the single digits, around 10F from highway 50 south in far southeast IL. A strong 1040-1044 mb arctic high pressure over Saskatchewan and northern High Plains to build into IL by sunset Sunday and weaken as it settles over the Southeast States on Monday. Mostly sunny skies Monday with more clouds from I-74 north. SW breezes develop on Monday but still cold with highs in the mid 20s to lower 30s, mildest from Macomb to Springfield sw.

After well below normal temperatures since Thanksgiving Eve, Pacific air is forecast to track into IL during mid week with strong temperature rises. Highs Tue in the mid 30s to lower 40s, in the 40s Wed and ranging from mid to upper 40s northern CWA Thu to low to mid 50s from Quincy to Lincoln to Champaign/Danville south (mid 50s in southeast IL). A storm system off the Pacific NW Coast to have a strong surface low of 980-984 mb track to near northern Lake Superior by midday Thu and bring a cold front through IL on Thu. This will bring rain chances overnight Wed night into Thu. Temps cool closer to normal Fri with highs in the mid to upper 30s, then warm back up on Saturday into mid 40s to lower 50s, mildest in southeast IL. Another cold front moving through Sat afternoon/evening to bring another chance of rain showers.

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AVIATION

(For the 18z TAFs through 18z Sunday Afternoon) Issued at 1155 AM CST Sat Dec 13 2025

Widespread moderate to heavy snows with vsbys down to 1/4 to 1/2 mile over central IL at midday while ceilings are 700-1k ft. Latest CAMs show the moderate snows diminishing from WNW to ESE between 19-22Z (ending at PIA 1st and CMI last). Flight conditions to lift to MVFR during mid afternoon and VFR during early evening as low clouds scatter out from 01-03Z. NNW winds 5-10 kts early this afternoon to veer NW and increase to 8-13 kts this evening and continue through midday Sunday.

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ILX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 8 PM CST this evening for ILZ027>031-036-037-040>042-047>054-056-061>063-066>068.

Cold Weather Advisory from 8 PM this evening to noon CST Sunday for ILZ027>031-036>038-040>057-061>063-066>068-071>073.

Winter Storm Warning until 8 PM CST this evening for ILZ038- 043>046-055-057.