The Great Lakes’ Strangest Phenomenon: Seiche

The Great Lakes consistently prove themselves to be a breed unlike any other. The size of the lakes dubbed "great" creates some truly unique situations for the states surrounding them. Counties and cities along the west coast of Lake Michigan must contend with lake effect snowfall due to the cooling effect of wind over the lake.

But there is an effect that many of us here in Michigan aren't familiar with, but that states like Ohio and New York tend to see around this time of year. It's something you've probably seen in a pool or bathtub, but this is on a much bigger scale.

I'm talking about the phenomenon known as a seiche.

What Is A Seiche?

A Seiche (pronounced saysh) is when strong winds and atmospheric pressures cause the water on the lake shore to be blown back, resulting in the water levels drastically decreasing in a short amount of time. However, that water has to go somewhere, and that "somewhere" is the opposite lakeshore.

Meteorologist Heather Waldman, who formerly hosted the web series "Heather's Weather Whys" with WGRZ in Buffalo, explained this phenomenon by describing how seiches occur in Lake Erie. While seiches occur in all the Great Lakes, due to Lake Erie being the shallowest of the Great Lakes, seiches are most extreme there.

The wind blows the water away from the Cleveland lakeshore, sending it to Buffalo's lakeshore and significantly raising the water levels. However, once the wind stops, the water "sloshes" in the other direction.

READ MORE: Did You Know Michigan Has Lake Effect Rain?

Like when you get in a bathtub, the water in the lake will go back and forth to the opposing lakeshores until the lake water eventually settles back to its usual level.

The following photos show a seiche at Crystal Beach in Buffalo in 2021, illustrating the significant fluctuations in water levels that can occur in the lake for hours and days at a time.

Is This The Same As A Meteotsunami?

If you're reading this and thinking, "Wow, that sounds just like a tsunami!", then you're not technically wrong. Michigan averages over 106 Meteotsunamis a year, and while both seiche and meteotsunamis' signature features are water receding, they are not the same thing.

Get our free mobile app

The NOAA states that while many tend to think they are the same and occur at the same time, winds usually cause seiches, while meteotsunamis are caused by pressure; their waves behave differently and occur more frequently in open water than in basins like Lake Erie.