textproduct: Chicago

KEY MESSAGES

- Potential for severe thunderstorms and heavy rain/localized flooding Tuesday afternoon into Tuesday evening.

- Unseasonably warm and breezy conditions through Tuesday.

- Possible pattern shift to colder with snow chances next weekend.

DISCUSSION

Issued at 145 AM CST Sun Mar 8 2026

Low clouds continue to shift east across the area early this morning and expect these to be east of the area by mid morning with mostly sunny skies today. High temps today will reach into the lower 60s for most areas and into the lower 70s on Monday. Southwest winds are expected to gust into the 25-30 mph range both days which will prevent any lake cooling. The models are showing a weak disturbance lifting northeast across the Ohio Valley Monday afternoon into Monday night with the southeast cwa on the northwest side of this wave. Some increase in cloud cover is possible though some of the cams are suggesting a few showers or sprinkles in the far southeast cwa. Confidence too low to include any mention at this time.

Attention then turns to a cold front moving south across the Great Lakes region Monday night as a storm system develops over the Plains and tracks northeast along this frontal boundary, which as trends show now would be across the local area/cwa. Temperature forecasts for Tuesday (especially for northeast IL) will be challenging over the next few days as the models vary with the location of the front. But temps south of the front may reach well into the upper 70s and may even tag lower 80s in a few spots. North of the front, temps could easily be in the 40s, to even upper 30s along the north shore. Eventually, fog mention will likely be needed for the nearshore waters and perhaps inland areas.

The cold front will slowly move south across northern IL, though whether that is earlier (Tuesday afternoon) or later (Tuesday evening) is uncertain, though a faster push south is certainly more probable this time of year. As the main surface low approaches, scattered thunderstorms are expected to develop during the afternoon. Some of these thunderstorms will have the potential to become severe, especially along and south of the cold front, wherever that location ends up being. In addition, with precipitable water values into the 1.5 inch range by Tuesday afternoon, which then continues into Tuesday night, heavy rain will be possible, which could train over the same areas leading to a localized flooding potential. Colder air spreading in behind this system could allow remaining rain on Wednesday to mix with or change to light snow. Though from this distance, it appears the snow would be light enough and temps marginal enough to prevent much of any accumulation.

The pattern then looks to remain active through next weekend with a clipper like system moving across the upper midwest and northern Great Lakes region Thursday night into Friday morning. Current trends would suggest the southern edge of the precip with this system may reach the northern cwa with a strong cold front possibly moving through the area Friday morning along with windy conditions.

While its way too early for specifics, there has been relatively good agreement among the models the past several days for a storm system across the region next weekend. The track of this system will be important for precip type and current blended guidance has some rain/snow mix during this time period. cms

AVIATION /12Z TAFS THROUGH 18Z MONDAY/

Issued at 627 AM CDT Sun Mar 8 2026

MVFR cigs will scatter across the Chicago-area terminals through 7-8 AM. VFR conditions are expected through the rest of the TAF period. SW winds will increase quickly this morning as mixing into the base of a departing LLJ ensues. Latest guidance indicates that winds could intermittently gust around 30-35 kts between about 16z and 20z. Thereafter, winds will ease a bit into the evening but are expected to remain at least periodically gusty at ORD and MDW overnight. At RFD and DPA, have introduced a period of marginal/modest LLWS given the expectation for the strongest gusts to subside. LLWS may need to be added to the rest of the Chicago-area terminals in future updates.

Carlaw

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...Small Craft Advisory until 6 PM CDT this evening for the IL and IN nearshore waters.