When communities situated near the Great Lakes experience extreme snowfall, particularly in recent days, meteorologists often reference the term “lake effect.”
Lake-effect snow frequently occurs in concentrated bands, resulting in substantial accumulations within localized areas. This weather event can lead to drastic variations in snowfall, where one region may be heavily blanketed while nearby areas see little to no snow.
Over the weekend, certain regions in upstate New York, Pennsylvania, Ohio, and Michigan received close to 4 feet (1.2 meters) of snow due to this phenomenon.
Understanding how lake-effect snow develops requires examining its process:
The formation begins when frigid air, often descending from Canada, moves over the relatively warmer waters of the Great Lakes. This warmer air from the lakes elevates moisture, pushing it into colder atmospheric zones where it can more readily form snow. According to Phillip Pandolfo, a meteorologist from the National Weather Service in Buffalo, New York, this moist air creates clouds that generate considerable snowfall downwind.
Interestingly, it is not the lakes that primarily supply the moisture needed for lake-effect snow. Instead, it is the pre-existing moisture content in the cold air that blows over the lakes. “Many believe the lakes are the main source of moisture,” Pandolfo explained. “In reality, the air needs to carry sufficient moisture before it interacts with the lakes.”
The right atmospheric conditions will lead to the development of clouds filled with moisture, which can deliver remarkably high snowfall rates. Policymakers can record intense snowfall events of 2 to 3 inches (5 to 8 centimeters) or more per hour. Since these clouds form narrow bands, adjacent towns may experience vastly different snowfall totals.
Forecasting lake-effect snow poses challenges; even slight shifts in wind patterns can significantly alter where the heaviest snow descends, according to the national weather agency.
For residents living near the Great Lakes, heavy snowfall is an expected part of winter life. Typically, a foot or two of snow (30 to 61 centimeters) is common, but some storms can be significantly more severe.
In November 2022, for instance, a series of lake-effect storms blanketed parts of western New York with over 6 feet (1.8 meters) of snow. These storms represented some of the heaviest accumulations in New York since at least 2014, when certain areas south of Buffalo were hammered with up to 7 feet (2.1 meters) of snow over three days, causing widespread disruptions, including damaged roofs and stranded cars along stretches of the New York State Thruway.
In Michigan’s Upper Peninsula, annual snow totals may exceed 20 feet (6 meters) as the lake effect intensifies winter storms, as indicated by researchers from the University of Michigan and Michigan State University.
This weather phenomenon is not exclusive to the Great Lakes; it can also manifest around other significant lakes, such as the Great Salt Lake in Utah.
