Some areas in the Northeast received over a foot of snow during Thanksgiving, with more snowfall projected for Saturday and throughout the weekend in parts of the Upper Great Lakes and Northeast, according to weather experts.

On Saturday, some sections of the New York Thruway had been cleared, yet remained closed, while Pennsylvania worked to clear its highways. Pennsylvania Governor Josh Shapiro called in the National Guard to assist stranded motorists and issued a disaster declaration for Erie County, advising residents to stay off the roads.

Forecasters predict intense lake-effect snow will bring significant snowfall from Lake Erie and Lake Ontario into the Buffalo, New York area throughout the weekend, potentially adding 1 to 2 feet of snow in certain locations, as per the local weather service.

The weather service in Buffalo cautioned on Saturday that snowfall could accumulate at rates of 1 to 3 inches per hour during heavier bands, making travel exceedingly difficult during those periods.

Within the most intense snow bands, conditions can resemble a blizzard, leading to substantial snow accumulation, while areas just outside these bands may experience much milder weather, according to AccuWeather. Travelers should be cautious, as conditions can change rapidly, turning potentially safe driving into dangerous situations.

“If a traveler gets stranded, the problem can quickly become a life-threatening emergency under these conditions,” warned AccuWeather’s Chief Meteorologist Jonathan Porter.

Forecast for Snow Across Multiple States

The National Weather Service noted that temperatures will be below normal in the Northern Plains, with heavy lake-effect snow impacting Michigan’s Upper Peninsula and parts of its Lower Peninsula until Monday. Snow from Lake Erie and Lake Ontario will also affect downwind states this weekend, including Pennsylvania, Ohio, and New York.

Further, light to moderate snowfall is expected in some areas of the Central Plains and Central Appalachians through Sunday, the weather service indicated.

The St. Louis weather service also provided warnings that intense snow bands could produce 3 to 5 inches, leading to hazardous conditions on the I-70/I-64 corridor.

Snow Forecast Details

The map below illustrates the likelihood of receiving more than 4 inches of snow in various areas. Adjust the slider on the top left to view different days.

Understanding Lake-Effect Snow

Lake-effect snow can persist from just a few minutes to several days. It typically occurs in the fall and early winter before lakes freeze over and is most common in the Great Lakes region, per the National Weather Service.

This phenomenon happens when cold air, often originating from Canada, blows over comparatively warmer water, leading to a transfer of heat and moisture into the lower atmosphere. As the air rises, clouds are formed that create a narrow snow band, causing lake-effect snow that can result in accumulations of about 2 to 3 inches of snow per hour.