DETROIT — It’s that time of year – again – when cold air sweeps across the Great Lakes, dropping massive amounts of lake-effect snow from Michigan’s Upper Peninsula to western New York.
Snow already started falling on Wednesday in and around Houghton, Michigan, and is expected to continue through Thanksgiving and into the weekend. A blizzard warning is in effect until Thursday morning for the Keweenaw Peninsula, where Houghton is located. According to the National Weather Service.
“The incoming system is producing some snow,” said Steve Considine, a meteorologist with the National Weather Service in White Lake Township, Michigan, northwest of Detroit. “Most of it is strengthened off the Great Lakes — the snow belt areas. That’s where they see the heaviest snowfall.”
The western part of Michigan’s Upper Peninsula is also under a blizzard warning with heavy snow and strong winds, Considine said, adding that the northern Upper Peninsula could see an accumulation of one to three feet (0.3 to 0.9 meters) of snow with most of the lake effect.
But what causes lake effect snow?
When cold air, often from Canada, blows over the Great Lakes region, it can cause weather problems in Michigan, Ohio, New York and other states in the region.
Warm air from lakes pushes moisture in the sky up into an area Most suitable for snowfall due to its temperature. Then clouds form, capable of throwing heavy rain downwind.
“You need open water in the Great Lakes, preferably with fairly warm water temperatures in the 40s,” Considine said.
Most of the moisture needed for lake-related snowfall does not actually come from the lakes, but from the cold air blowing above them. Add a fairly consistent wind direction and the right conditions can be created for heavy snowfall.
Temperatures Wednesday night in Houghton are expected to drop to 20 degrees Fahrenheit (7 degrees Celsius) and are expected to remain below freezing through Saturday.
From that usually come thin bands of clouds that can produce heavy snowfall — 2 to 3 inches (5 to 8 centimeters) per hour and sometimes more. Because the ranges are narrow, snowfall may vary from place to place.
The Kalkaska area in northwest Michigan’s Lower Peninsula will likely see more than a foot (0.30 m) of snow. However, Grand Rapids, Michigan, which lies just east of Lake Michigan, could see 2 to 5 inches (5 to 12 cm) of snow, while nearby Kalamazoo could get 4 to 8 inches (10 to 20 cm).
Lakeshore snow from the current storm system moving through Michigan “loses its density as it moves away from Lake Michigan,” Considine said.
Other very large lakes, including Utah’s Great Salt Lake, can experience lake-effect snow, but its wrath is more common along Lakes Superior, Michigan, Huron, Erie, and Ontario.
Communities off Lakes Erie and Ontario, to the east, could be trapped by the current storm system. A wide area of western New York is already under a lake effect snowfall warning.
Temperatures in Buffalo are expected to drop into the low 30s Wednesday night, according to the National Weather Service, and stay in the 30s through Saturday.
Up to 18 inches (30 to 46 cm) of snow is expected south of Buffalo, while 6 to 10 inches (15 to 25 cm) could fall near Watertown, New York, Considine said.
“There have been some really big events in the Buffalo area,” Considine said. “Buffalo is really the king of the lake effect. They’ve got the band coming in from Lake Erie. It’s relatively shallow and warm in the first part of the winter.”
Lake-effect storms dropped more than 6 feet (1.8 meters) of snow in western New York November 2022. The winter storms were the worst in New York since at least November 2014, when some communities south of Buffalo were hit with up to 2.1 meters of snow over three days, collapsing roofs and trapping drivers along New York State Highway.