The Chicago area is under a Level 2 for severe weather on Sunday.
ABC7 meteorologist Jaisol Martinez said strong storms could bring damaging winds, and possibly flash flooding on Sunday.
The morning had a calm start with temperatures in the 60s. Humidity is expected to increase throughout the day and highs will reach into the mid-80s.
Martinez said the first round of storms could arrive between 1 p.n. and 4 p.m.
Then the second round of more widespread storms develops between 8 p.m. and 10 p.m.
Martinez said if the first round of storms overperforms, then the second round might not happen.
The Chicago area is under a Level 2 out of 5 for severe weather.
Monday is also an AccuWeather Alert day. Meteorologists are keeping an eye on how storms develop to the north and west.