ASK TOM: Lake Michigan waves in winter vs summer

Dear Tom,

As an avid recreational boater on Lake Michigan for many years, I have noticed the lake’s waves are higher in the winter than in the summer. What is the explanation?

Bill Roberts, Waukegan

Dear Bill,

Any given wind speed, say 15 knots, will build higher waves in the winter than in the summer. Cold air over warm water (the winter situation) transfers more wind energy to the water than does warm air over cold water (the summer situation). When cold air blows over warm water, the air heats, lifts off the water and is replaced by stronger winds from above. Strong winds are constantly sinking to the lake surface. In summer, it’s just the opposite. Cool, calm air hugs the water and strong winds remain aloft. The net effect is that wind speeds over the surface of Lake Michigan are higher during the winter than in the summer.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s