textproduct: Chicago

KEY MESSAGES

- Milder temperatures expected for much of the upcoming work week.

DISCUSSION

Issued at 134 AM CST Sun Feb 8 2026

Snow associated with a region of stout low-level frontogenesis continues to shift east early this morning and is ending in our forecast area. Some lingering mid-level moisture associated with the primary 700 mb shortwave will drift out of southern Wisconsin, but additional precipitation appears unlikely with this through daybreak. The pressure gradient will steadily increase across the area this morning as a modest surface low currently across eastern South Dakota drifts eastward and slowly fills. This will lead to increasing southeasterly breezes today, and some additional mid-level cloud cover will likely develop with time. Persistent onshore flow will also lead to an expansion of low stratus mainly across parts of Lake County, IL, but cloud depths appear too limited to support much a precipitation threat.

Warm advection will increase late tonight into Monday morning as another surface low spins up across South Dakota. In response, moisture within the 925-800 mb layer is forecast to increase a bit into early Monday morning. At this point, suspect that the NAM is suffering from its typical moist bias, with limited support for the degree of saturation it's advertising across the rest of the guidance suite. As a result, precip chances don't appear necessary at this time.

The aforementioned low is forecast to scoot east into Iowa on Monday afternoon. As this occurs, boundary layer flow across northern Illinois will begin to turn southerly and eventually southwesterly Monday night. This in turn will drive a warmer airmass northward, with highs on Monday looking likely to push well into the 40s across the southwest third of the forecast area, with mid/upper 30s expected to linger across far northeast Illinois and northwest Indiana.

Eventually, a cold front will shift across the region either very late Monday night or Tuesday morning. The signal for any precipitation with this front/trough isn't particularly robust, likely due to progged limited low-level moisture. That said, some guidance looks close to supporting drizzle (UKMET and NAM and particular), although again this doesn't have a lot of support across the rest of the guidance suite at this time, so did not see a reason to introduce a weather mention at this point. In the wake of this front, a brief period of cold advection will diminish through the afternoon which should allow temperatures to push back into the 40s across much of the area.

High pressure will build into the region through Wednesday night. Thereafter, several disturbances are forecast to track across the central CONUS and Midwest. Some potential for wintry precipitation is evident, but significant spread across the deterministic and ensemble model suite exists leading to low confidence in the forecast evolution Thursday into next weekend.

Carlaw

AVIATION /06Z TAFS THROUGH 12Z MONDAY/

Issued at 1048 PM CST Sat Feb 7 2026

Key Messages for the 06Z TAFs:

- Narrow NW-SE band of snow exiting the Chicago terminals early in the TAF period. Brief MVFR/IFR during this snowfall.

A narrow northwest-southeast band of light snow over ORD/MDW/GYY just prior to TAF issuance will move quickly east of the terminals well before daybreak. GYY may still experience snow at 06Z, while ORD and MDW may see snow end around the start of the period. Will see quick improvement from IFR/MVFR to VFR conditions as snow moves east.

Otherwise, VFR conditions are expected through the period, along with east-southeast to southeast winds around 10 kts as a weak area of low pressure passes well south of the region.

Ratzer

LOT WATCHES/WARNINGS/ADVISORIES

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