textproduct: Chicago

KEY MESSAGES

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

DISCUSSION

Issued at 230 PM CST Sun Feb 8 2026

Low-level warm air advection is progged to gradually increase over the area tonight as a 1002 mb surface low tracks eastward across southern Manitoba and a secondary surface low attempts to become better defined south of it. Could see some attempts at renewed stratus development into tomorrow morning as isentropic lift helps moisten the 800-950 mb layer, but model guidance as a whole still suggests that low-level saturation won't be deep or widespread enough to support the development of drizzle. Even the overly-moist NAM has trended lower with its degree of low- level moisture, so have maintained a dry forecast for tonight into tomorrow.

Warm air advection at the surface should become more apparent tomorrow as winds turn southerly. In spite of increasing and thickening upper-level cloud cover, these southerly winds should help push temperatures into the 40s across primarily western portions of our forecast area. Farther to the east (particularly in areas where a relatively deeper snowpack remains in place), highs will likely only top out in the mid- upper 30s.

The cold front associated with the aforementioned low pressure center(s) will eventually reach northern Illinois tomorrow night and track across our forecast area from northwest to southeast during the overnight/early morning hours. A few models continue to indicate that there is some potential for drizzle near/along the front. However, the signal for that in those models does not look all that robust, and with the majority of forecast guidance still favoring a dry frontal passage in the absence of better low-level moisture, have continued to withhold on a formal drizzle mention in the forecast grids.

While an initial push of cold air advection behind the front may stunt diurnal warming attempts in the hours just after sunrise, it nevertheless still appears that the frontal passage may occur early enough for increasing quantities of sunshine to push temperatures back into the 40s across a large portion of our forecast area once again during the afternoon. Northwesterly winds will then continue into Wednesday, when high temperatures are expected to be a bit cooler (though still near to above normal for this time of year). Dry conditions will also persist for a while longer as surface high pressure builds into the region late Wednesday into Thursday morning.

Multiple upper-level disturbances are then forecast to track through the central CONUS during the latter half of the week and over the weekend. Depending on their exact evolution (and the location and strength of the aforementioned surface high as it settles somewhere near or east of our area), our next opportunities for wintry precipitation may arise -- primarily focused during the late Thursday-early Friday time frame and again sometime over the weekend. However, ensemble spread remains quite vast from Thursday onward, and there are multiple potential outcomes that keep most or all of the precipitation west and south of our forecast area over the latter half of the forecast period. The lower-end chance PoPs offered by the NBM during the time frame in question thus continue to look reasonable from this vantage point.

Ogorek

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 1053 PM CST Sun Feb 8 2026

Key Aviation Messages for the 06Z TAFs:

- Southeast winds will become southerly by late Monday morning. May see brief periods of 160-170 deg for ORD especially early Monday evening.

- Period of LLWS likely late Monday evening/overnight with SW winds 45+ kts 1500-2000 ft AGL.

Surface high pressure centered east of the forecast area will continue to maintain modest southeast winds across the terminals into early Monday morning. The high will begin to drift east by mid-late morning, allowing winds to veer south by midday. Direction is expected to be in the 170-190 deg range, with the greatest potential for a brief period of 160-170 deg early Monday evening. Winds then gradually turn southwest late Monday/evening overnight, possibly with some sporadic gusts around 20 kt. Current model guidance depicts development of a WSW 45-55 kt low level jet above 1500 ft agl late Monday evening/overnight, which would support a LLWS threat overnight. A cold front will then approach from the west toward the 12Z end of the ORD/MDW forecasts. There are some model differences with the exact timing of the front for ORD/MDW, with some guidance indicated fropa just beyond 12Z.

Cloud-wise, a ribbon of 5-6 kft stratus has stalled across the area since sunset and looks like it will persist into Monday morning with some gradual lowering into the 3500 ft range before scattering out and shifting east. Otherwise, mainly mid-level VFR (15 kft and above) cloud cover through the remainder of the TAF period.

Ratzer

LOT WATCHES/WARNINGS/ADVISORIES

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