textproduct: Chicago

KEY MESSAGES

- A slight chance for some pockets of very light rain or sprinkles late this evening and tonight.

- Generally dry conditions expected through much of the upcoming work week with the next appreciable rain chances not until Friday into next weekend.

DISCUSSION

Issued at 243 AM CDT Sun May 31 2026

Today's weather should be very similar to yesterday's. After starting the day in the 50s, afternoon temperatures will warm into the 80s around most inland areas with 60s and lower 70s anticipated around Lake Michigan. High pressure centered out to our east will provide light easterly winds today with a breezier push anticipated behind an inland-moving lake breeze during the latter part of the day. We'll see a fair mix of clouds and blue sky, although cloud cover will be thickening up later in the day.

Later this morning, a weak shortwave impulse will eject east out of the central Plains and work across the region tonight atop a building southern stream ridge. This wave will shunt a deep baroclinic zone east into our vicinity and provide an opportunity for some light rain late today into tomorrow. Some guidance is resolving light simulated radar returns in our west as early as this afternoon as the wave begins advancing across the Mississippi. However, a great deal of dry air through the lower part of the column and a general lack of forcing should make precip development difficult to achieve prior to dusk.

The late evening and overnight period appears to harbor the greatest precip potential when we'll find the deepest layer saturation with the baroclinic zone overhead and seemingly greatest forcing with the primary vort lobe associated with this wave working across. Guidance varies between a dry forecast and a decent concentration of true light showers, and the discrepancies boil down to the strength of the wave and the amount of low level dry air to eat away at precip. At this point, the most likely scenario appears to be isolated instances of very light rain or sprinkles through the night, although a few, more appreciable showers can't be ruled out. There is some support for additional precip during the day on Monday as the baroclinic zone gets hung up in the vicinity. Guidance favors even more dry air feeding in after daybreak and a continued lack of forcing, so not anticipating any precip beyond early morning at this point.

The blocking upper air pattern responsible for the quiet weather these past several days will begin breaking down over the Hudson Bay today. It will slowly shear out across the Great Lakes through Thursday and park another prominent surface high over the region during the middle part of the week. This should keep any mid-week rain chances at bay while afternoon temperatures continue hitting the upper 70s and 80s. Late this week after the high finally pushes off the east coast, a synoptic system is favored to move across the region and bring a chance for some rain on Friday, the best chance that we see over the next week. Ahead of the wave, a warmer air mass will advect into the region. There's a good amount of spread in temperature guidance for late week, but support is there for near 90 degree temps Thursday and Friday.

Doom

AVIATION /12Z TAFS THROUGH 18Z MONDAY/

Issued at 559 AM CDT Sun May 31 2026

Winds will be predominantly southeasterly this morning but will shift out of the northeast during the afternoon behind a lake breeze which will eventually sweep across RFD early this evening. There is a chance for some sprinkles this evening and overnight into Monday morning, but have left a mention out at this time due to the generally small chances and low operational impacts.

Carlaw

LOT WATCHES/WARNINGS/ADVISORIES

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