ABC7 Chicago Meteorologist Cheryl Scott explains the winter wonder.
Earlier this week, ice pancakes formed in Lake Michigan right along the Chicago shoreline.
This occurs when near to below freezing temperatures settle into the region when the water temperature is just above freezing, Scott said. This results in a thin layer of ice and slush.
Due to the swirling movement of the water, the ice breaks apart and forms into circular disks. As these disks bang into each other, it helps form their outer ridge.