textproduct: Chicago

KEY MESSAGES

- Looking increasingly probable that most, if not all of our CWA, will be missed by Wednesday night's snow.

DISCUSSION

Issued at 1249 PM CST Tue Feb 24 2026

Through Thursday...

Gusty winds will diminish early this evening and then shift to the west behind a cold front that will move across the area this evening. Still can't totally rule out a few sprinkles or flurries/snow pellets, but chances of any measurable precipitation are very low. Skies will begin to clear out tonight with mostly sunny conditions expected Wednesday. While the air mass behind the front will be a bit cooler, the addition of sunshine tomorrow should allow temps to still climb into the 30s.

Guidance, other than the operational GFS, has largely trended south with the Wednesday night system with little or no precipitation in our CWA. Given not all that much support from its ensemble suite, have largely discounted the 12z operational GFS and trended lower with pops/QPF. Opted to hang onto some low pops south of I-80 Wednesday night on the off chance the 12z GFS pans out, but the more likely scenario is that it will join the rest of the models and later forecasts will be able to remove pops altogether.

- Izzi

Thursday Night through Tuesday:

Weak high pressure will help clear skies out Thursday night and keep temperatures in the 20s (maybe low 30s near the lake). Winds on Friday are expected to be out of the southwest, driving better warm air advection. Temperatures are expected to climb back into the 40s and potentially even the 50s. However, the warm up will be short lived.

Models are projecting an upper level closed low to dive down through central Canada toward southeastern Ontario. Highest confidence with this system is the return of temperatures in the 20s and upper 30s. The NBM has increased PoPs to 20 to 40 percent chance for areas north of I-88. Plenty of members are showing something over that area, but model soundings are showing a lot of dry air over the area which may limit impacts.

Fairly zonal flow is projected to develop early next week. Weak perturbations could allow for additional chances for precipitation next week. Ensembles are honing in on Monday morning being the target for accumulating snow. However there are a lot of discrepancies to have confidence in the exact details of amounts and timing. Whatever does develop will likely keep colder temperatures for the early part of next week. But for those that prefer milder weather, early indication is that there could be a gradually warming of temperatures through next week toward next weekend!

DK

AVIATION /06Z TAFS THROUGH 12Z THURSDAY/

Issued at 1105 PM CST Tue Feb 24 2026

Skies have since cleared out in the wake of this evening's scattered light snow showers. We are monitoring an area of MVFR stratus currently across Minnesota and NW Wisconsin. The majority of guidance has this thinning and decreasing in coverage as it approaches northern Illinois. Can't rule out a period of MVFR in the morning on Wednesday if these clouds hold together though confidence isn't high enough to include with this update.

Winds will be sporadically gusty out of the west northwest during the early overnight hours with prevailing gusts in the 20-25 kt range expected by early Wednesday morning. Winds then quickly diminish toward sunset.

Dry conditions are forecast through the period with the next system expected to remain well south of the terminals Wednesday night.

Petr

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...Small Craft Advisory until 10 AM CST Wednesday for Winthrop Harbor IL to Gary IN.

Small Craft Advisory until 4 PM CST Wednesday for Gary to Burns Harbor IN-Burns Harbor to Michigan City IN.