The Detroit Free Press reports that massive waves of up to 20 feet in height are forecast for Lake Michigan:
An intense low pressure system is still projected to slam into the western Great Lakes on Wednesday night.
The main hazard with this storm will be incredibly strong winds in excess to 45 m.p.h. at times. This will cause numerous issues, including downed trees and the potential for power outages.
In addition to impacts on land, Lake Michigan will also suffer the wrath of this strong fall storm, where waves could reach as high as 20 feet offshore. A gale watch has been issued by the National Weather Service in Grand Rapids for the Lakeshore and will be in effect from Wednesday evening through Friday afternoon.
NOAA’s Great Lakes Coastal Forecasting System has a ton of resources for visualizing live data and forecasts for all of the Great Lakes. Be sure to check out the animation of forecasted wave heights on Lake Michigan – pretty cool to watch. In case you’re wondering, the tallest (recorded) wave on Lake Michigan is 23′ from September of 2011. Of course the bouys shut down for the winter in December, and they only started measuring in 1988.