WKBW-TV, Buffalo — It's summer, so that means a lot of us think about going to the beach.
Our oceanfront beaches, as we know, have tides. But did you ever wonder if our own Great Lakes in our backyard have tides? Well, the answer may just surprise you.
Ocean tides are very predictable and are caused by the gravitational forces of the moon and the earth, as well as the Earth and moon’s orbit around each other. This begs the question, can the same forces cause tides on the Great Lakes?
The answer is, sort of.
Studies show that a tide, by definition, does occur twice a day on the Great Lakes, but are so inconsequential that at their highest they are less than five centimeters in height. These minor variations are masked by the greater fluctuations in lake levels produced by wind and barometric pressure changes.
Wind and weather conditions on the Great Lakes may create a seiche, an oscillating wave that can be several feet high. In many of the Great Lakes, the period between the “high” and “low” of a seiche may be between four and seven hours. As this is very similar to the six-hour time period of the tides on the ocean, it is frequently mistaken for a tide.
So, while our lakes are “Great," compared to the planet’s oceans, they are comparatively much smaller. That’s why scientists consider our Great Lakes non-tidal.
So now you know that levels of water on the Great Lakes are driven more by forces that are meteorological in nature. Got a weather question that you'd like answered? E-mail me at weather@wkbw.com, and your weather question could be the subject of the next Josh's Weather Academy.
