textproduct: Chicago

KEY MESSAGES

- Chance (20-30%) for a wintry mix across far northern IL Sunday evening.

- Above average temperatures expected much of next week.

DISCUSSION

Issued at 302 AM CST Fri Jan 2 2026

Through Tonight:

Quiet conditions will persist here in the short term. Early this morning, the area sits beneath a low level stratus deck that's slowly been filling in from the north since yesterday afternoon. Guidance is doing an awful job at resolving these low ceilings and, as a result, temperature guidance is also struggling this morning. We've managed to stay a few to several degrees warmer than just about all guidance during the night with a number of sites even having warmed a degree or two since last evening. Some clearing over south-central WI is spreading south as drier BL air fills in. This should chip away at the stratus locally during the morning hours with most of today expected to offer up a mix of clouds and sunshine.

Given the milder conditions to start the day, bumped daytime temperatures today a degree or two higher than some of the warmer camps to get middle 20s around a majority of our area to around 30 degrees in our far south. While winds will be generally light, conditions may feel more like the teens and lower 20s for the better part of the day. Broad high pressure beneath a regional NW upper flow pattern will keep precip chances at bay today. Lows tonight are forecast to drop into the teens to around 20 degrees.

Doom

Saturday through Thursday:

Conditions will remain seasonably chilly through the weekend, with high temperatures around 30 and overnight lows in the teens. While most areas will remain precipitation free through the weekend, we will be monitoring a low amplitude clipper type impulse that will be tracking eastward across the Upper Great Lakes on Saturday. Most, if not all of the precipitation potential with this impulse will remain north and northeast of our area. However, we certainly cannot rule out the possibility of a few snow flurries sneaking as far south as parts of far northeastern IL Saturday morning. This appears to be the worst case scenario at this time, as a rather parched low-level airmass should largely curtail the precipitation threat with southward extent.

Upper ridging across the western CONUS into Saturday will build eastward through the weekend, ultimately fostering a shift towards a milder quasi-zonal (west-to- east oriented) mid and upper-level flow pattern across our region by early next week. This warmer pattern will be kick started Sunday night as warm air advection quickly ramps up across much of the Midwest into the Great Lakes region in advance of the next impulse tracking into the Upper Midwest. Accordingly, this is expected to result in nearly steady (or even slowing rising) surface temperatures in the upper 20s to the low 30s Sunday night, followed by temperatures warming into the 40s for daytime highs Monday.

While we will be trending in a good direction with temperatures into Monday, there is some concern for a period of light freezing precipitation across parts of northern IL Sunday night. This as, our area looks to reside along the southern periphery of a developing warm air advection induced precipitation shield Sunday night. Overall, this does not look to be a big icing event for any of our area, but the potential does exist for a period of freezing precipitation across portions of far northern IL (north of I-88) Sunday night before temperatures warm above freezing Monday morning. We will continue to monitor this potential.

Temperatures Monday through the remainder of the work week are expected to be above average, with highs generally in the 40s (possibly near 50 at times) and overnight lows in the 30s. Generally dry weather is anticipated, though we will see some increased chances for rain with another potential storm system for the second half of the week.

KJB

AVIATION /12Z TAFS THROUGH 18Z SATURDAY/

Issued at 500 AM CST Fri Jan 2 2026

There are no significant aviation weather concerns anticipated through the period.

A persistent high MVFR stratus deck continues to hang on across the terminal airspace early this morning. However, recent satellite trends suggest that this deck of stratus will begin to scatter from north-to-south across the Chicago area terminals after 12Z this morning. Accordingly, we should experience a quick return to VFR conditions across the airspace through the early and mid morning hours today.

Winds will remain light (5 to 10 kt) from the northwest through the day, then trend more north-northwest tonight into Saturday morning.

KJB

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...None.