Gusts as high as 60 miles per hour are expected. Preparations were under way Monday night to secure anything that could come loose. Winds that powerful can create dangerous situations including flying debris and power outages.
While Chicago won't have as much rain, forecasters expect dangerous wind gusts may be around for 36 hours or so. It's expected to be a consistent pounding, lasting longer than most tropical storms or hurricanes.
Some people were tying down anything that could fly Monday night.
"We have notified everyone in the city of Chicago right now, particularly cranes or anything out there that may pose a hazard. The idea behind this is to get the word out there," said Jose Santiago, Chicago Emergency Management.
The danger is real. In 2002, 60 mile per hour wind gusts tore window washing equipment loose from the side of the John Hancock Building. It fell 43 stories, killing three people in cars below.
Strong, sustained winds also threaten to bring down power lines so Monday night Com Ed was staffing up.
The utility is anticipating the most severe threat to its electric grid in decades. Com Ed has opened its emergency operations center, added crews and is telling them to expect to work 16-hour days to restore power outages caused by the wind storm.
"It's common sense, right? You're going to have wind pushing on trees, breaking limbs. You're going to have some power outages out there," said Mike Guerra, Com Ed.
Officials also warn residents to remove Halloween decorations that could fly away.