Thundershowers with heavy rain and cloud to ground lightning are possible, with most lasting 30 minutes or less.
Thundershowers with heavy rain and cloud to ground lightning are now 23 miles southwest of downtown Chicago. If these storms hold together, heavy rain and lightning are on the lakefront and the #chicagoairandwatershow by 11:45am. pic.twitter.com/M6XXNqhvD4— Mark McGinnis (@MarkMcGinniswx) August 17, 2019
Some clouds will begin to thin out starting mid-afternoon through the early evening hours. This could provide enough time for one or two stronger storms capable of strong winds and large hail to develop for western suburbs.
If you are outside and hear thunder, the safest decision is to move indoors or inside a car to reduce the threat of a lightning strike.