FXUS63 KILX 121802

AFDILX



Area Forecast Discussion...Updated Aviation

National Weather Service Lincoln IL

1202 PM CST Fri Dec 12 2025



.KEY MESSAGES...



- A quick hitting winter system will bring accumulating snow on

  Saturday. There is high confidence of seeing at least 3 inches

  of snow north of a Springfield to Mattoon line.



- Dangerously cold wind chills are expected both Saturday and

  Sunday nights. The coldest wind chills will drop as low as 15 to

  25 degrees below zero.



&&



.DISCUSSION...

Issued at 256 AM CST Fri Dec 12 2025



Surface low pressure is passing by to the south of here early this 

morning with light snow continuing to fall north of it across 

central Illinois. Snow reports late Thursday evening ranged from 2 

to 4 inches, with additional snow amounts looking to remain below 1 

inch this morning. Precipitation will come to an end by daybreak,

with cold and mostly dry conditions expected today. High 

temperatures were lowered by several degrees due to increased 

cloudiness. Forecast highs will peak in the upper 20s to middle 

30s.



Accumulating snow returns on Saturday as an upper disturbance 

originating from the Canadian Prairies dives southeast into the 

Great Lakes Region. A cold front tied to this system will work 

through the area later today, bringing an arctic push of air 

southward. Overnight lows tonight will dip down into the single 

digits to teens for most, with low 20s south of I-70. Snow will 

begin nosing into west-central Illinois by daybreak Saturday ahead 

of an upper shortwave with precipitation chances quickly spreading 

east through late morning. Snow will continue through most of the 

day before coming to an end Saturday evening. Forecast soundings 

show deep moisture with synoptic lift/DGZ depth supporting 

occasional bursts of moderate to heavy snow, especially north of I-

72 where strong ~600-700 mb frontogenetic banding looks to slide 

through late morning into early afternoon. The 12.00Z HREF has a 40-

70% chance for greater than 1 inch/hour snowfall rates in this same 

area, which could result in a narrow band of heavy snow potentially 

exceeding 6 inches. Confidence is high (50-80% chance) in seeing at 

least 3 inches of snow north of a Springfield to Mattoon line 

through Saturday evening. However, lower confidence remains in 

regards to the upper end amounts. 



Strong high pressure drops into the middle Mississippi Valley for 

the second half of the weekend, bringing bitterly cold temperatures 

over a fresh snowpack. Overnight lows Saturday night will fall into 

the negative single digits with brisk northwest winds sending wind 

chills as low as -25 degrees. Similar conditions are expected Sunday 

night, though somewhat lighter winds will keep minimum wind 

chills in the single digits to teens below zero. Cold Weather 

Advisories will likely be needed both of these nights.



Southerly return flow will bring a warming trend heading into the 

new week, with high temperatures possibly climbing into the 40s by 

mid to late week. Cloud cover and a residual snowpack could truncate 

this though, which is evident by the large spread in temperature 

forecasts. Precipitation chances look low through most of the 

week with longer range guidance showing chances increasing by the 

end of the week.



NMA



&&



.AVIATION...  (For the 18z TAFs through 18z Saturday Afternoon)

Issued at 1202 PM CST Fri Dec 12 2025



MVFR to IFR cigs remain across central IL, with the MVFR being

predominant along the I-74 terminals. Any improvement through the

upcoming 12-18 hours appears uncertain, with perhaps a brief

period of improvement before snow begins to move into the area

from 12Z-14Z and increases in intensity. A return to IFR cigs

appears likely, and vsby will likely transition to LIFR by 18Z.

Winds shifting from NE to NW around 5-10 kts early in the period.



37



&&



.ILX WATCHES/WARNINGS/ADVISORIES...

None.

&&



$$