Winter Wonder: What is 'pancake ice' on Lake Michigan, how does it form?

ABC 7 Chicago Meteorologist Cheryl Scott explains
CHICAGO (WLS) -- You may have noticed pancake or donut-shaped chunks of ice floating on the surface of Lake Michigan, but what exactly is it and how does it form?

ABC7 Chicago Meteorologist Cheryl Scott explains the winter wonder.

Earlier this week, "ice pancakes" formed in Lake Michigan right along the Chicago shoreline.

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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.

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The result: "Ice pans" or "ice pancakes" layered across the lake.

This phenomenon isn't that uncommon but doesn't happen too often, Scott said.

These ice disks are the beginning phase of ice formation on Lake Michigan. With arctic air settling into the region for a period of time, expect sheets of ice to form.

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