CNN  — 

A broad swath of the US won’t have to dream of a white Christmas as winter weather bears down on much of the Northwest, Midwest and Northeast on Sunday. They’ll be seeing snow from two separate storms.

More than 60 million people live in areas that are under winter weather alerts, which includes advisories, warnings and lake-effect snow warnings.

A storm system that was located over Des Moines, Iowa, and Kansas City on Sunday morning was moving eastward.

The storm began affecting Chicago around 10 a.m. and Detroit and Cleveland by the early afternoon. Heavy snow should begin in Buffalo, New York, and Pennsylvania after 8 p.m., and snowfall amounts of 2 to 4 inches are expected across a wide band of the Northeast.

Certain narrow bands in upstate New York could see major snowfall totals of 2 feet or more due to lake-effect enhancement. The National Weather Service forecast for the area included totals as high as 50 inches in specific parts.

In addition, a new storm system is moving into the Pacific Northwest with up to 2 inches of snow expected in Seattle and a mix of ice and snow in Portland, Oregon.

The system will then move into Colorado Sunday night through Christmas Day, which could affect travel conditions.

Severe winter weather is possible in southeast Wyoming, where a blizzard warning goes into effect early Monday morning, the weather service said. An area along Interstate 80 could see up to 6 inches of snow accumulation and 50 mph winds, causing whiteout conditions.

The wintry weather may cause some delays and other difficulties – both on the roads and in the skies – during one of the busiest times of the year.

According to FlightAware, more than 3,100 flights arriving in, departing from or operating within the US were delayed as of 5:30 p.m. ET Sunday.