textproduct: Chicago

KEY MESSAGES

- Seasonable temperatures with dry conditions are expected through much of the upcoming week.

DISCUSSION

Issued at 100 AM CDT Mon Oct 5 2026

There isn't much to discuss in the weather department over the short term with a sprawling mid 1020 mb high building across the Great Lakes region. Tranquil and pleasant conditions are in store today and tonight. Energetic northwest flow aloft will continue across southern Canada, and another deepening surface low will shift east towards the James Bay through the middle of the week. As this occurs, broad southwesterly flow will intensify across our area on Tuesday. Fairly deep mixing into the base of the stronger flow aloft will result in late morning and afternoon breezes, with some gusts into the 25-30 mph range appearing more likely across northern Illinois. Dewpoints are likely to mix out into the low to mid 40s, yielding 30-40 percent afternoon RHs. The overlap of the strongest winds (north) does not look to coincide with the driest conditions (south) at this time.

A "cold front" will push through the area early on Wednesday. While we'll be modestly cold advecting, deep mixing behind the boundary will yield similar or even slightly warmer conditions compared to Tuesday along with some lingering northwesterly breezes.

A fast-moving, low-amplitude wave embedded within the expansive belt of cyclonic northwesterly flow is forecast to drift across the area Thursday night into Friday morning. Somewhat ephemeral and disorganized f-gen forcing may interact with a plume of modestly steepened mid-level lapse rates resulting in a chance for some sprinkles or light showers in spots on Friday, although a parched sub-cloud airmass should limit greatly precipitation coverage.

Next weekend currently looks to remain precipitation-free and warm as southwesterly flow delivers near +15 to +20 C 850 mb temperatures to the region which may result in a smattering of low to mid 80 degree high temperatures in spots.

Carlaw

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 1206 AM CDT Mon Oct 5 2026

VFR conditions will persist through the period. NNW winds around 5 knots will shift east of north between 13 and 15Z at ORD/MDW, then settle ENE/E up to 10 knots with a lake-enhanced push mid to late afternoon. Winds will then slowly veer from ESE early in the evening to SSE/S by daybreak Tuesday.

Kluber

LOT WATCHES/WARNINGS/ADVISORIES

IL...None. IN...None. LM...Small Craft Advisory until 10 AM CDT this morning for Burns Harbor to Michigan City IN.