How high are the largest waves ever recorded on Lake Michigan?

Dear Tom,
How high are the largest waves ever recorded on Lake Michigan?

Cory Milgante,
Benton Harbor, Michigan

Dear Cory,
Waves (other than tsunamis or other non-wind produced waves) are generated by wind blowing across an expanse of water for a period of time. In general, the stronger the wind, the longer the expanse of water (fetch), and the longer the duration of the wind, the higher the waves. On the open ocean, where fetch can be several thousand miles, wave heights can exceed 50 feet. They can even approach 100 feet in intense storms. In contrast, wave heights on the Great Lakes are greatly limited. Lake Superior, the largest of the Great Lakes, experiences the highest waves, topping out at about 30 feet. Marine forecasters at the National Weather Service office in Romeoville say the highest waves on Lake Michigan are 20-23 feet in height.