Warmer Great Lakes could fuel a snowier season ahead

Why warm Great Lakes could mean heavy lake-effect snow this winter

The Great Lakes are unusually warm this fall — and that could have a big impact on the upcoming winter season. Fox Chicago meteorologist Mike Caplan explains how higher lake temperatures could trigger major lake-effect snow earlier and more intensely than usual.

CHICAGO - The Great Lakes are unusually warm for this time of year, which isn’t a surprise given the unseasonably warm weather the Great Lakes Region has been experiencing since the start of Meteorological Fall.

Meteorological Fall is the three month period from September 1st to November 30th. September finished with an average temperature of 69.3 degrees, which is 3 degrees above average. So far in the month of October, nearly every day has been near or above average.

So how could the warmer waters of Lake Michigan impact our local forecast? It could mean more lake-effect snow as the weather turns colder in the coming months.

Lake effect snow is common in our region during the late fall and winter months. It develops when cold air moves over the relatively warmer waters of the Great Lakes, and in our case, Lake Michigan.

As the air immediately above the water warms, it then rises and condenses, forming clouds and bands of precipitation. The larger the temperature difference is between the water temperatures and the air above it, the higher potential for lake effect snow to develop and pile up given the right conditions.

Wind direction plays a key role in determining where lake effect snow bands set up, and where they don’t. So while this year’s warm lake temps boost the potential for heavier snow later on, we’ll still need the right mix of cold air, moisture, and wind direction to make it happen.