A blast of Arctic air taking over much of the U.S. this weekend is bringing powerful lake-effect snow to several states, including Pennsylvania and New York, and shivering temperatures to parts of the South.

Winter alerts including lake-effect snow warnings have been posted for parts of Wisconsin, Michigan, Ohio, Pennsylvania, and New York state for this weekend, with some in effect through Monday evening.

As cold air passes over the relatively warm water of the Great Lakes, significant lake-effect snow bands are expected to blanket several communities with snowfall.

Overall, the cold air mass is bringing below-freezing temperatures as far south as the Florida panhandle, and more than 13 million people across nine states in the south are under freeze alerts.

The highest snow totals this weekend are expected around Watertown, New York, where 3 to 5 feet of snow is in the forecast. The narrow and intense bands of snow can deliver localized whiteout conditions, making travel nearly impossible.

A second band of heavy snow is expected to stay mainly south of Buffalo, with the area around Dunkirk, New York, looking at more than 3 feet of snow this weekend.

In Erie County, New York, which includes Buffalo, officials are urging caution.

“This is going to be a serious storm, especially in the southern parts of Erie County,” Erie County Executive Mark Poloncarz said during a news conference Friday. “If you don’t have to drive, stay home. It’s not worth the risk.”

Driving could be hazardous, according to Poloncarz.

“We’re talking about whiteout conditions where you can’t see anything while driving,” he said. “It’s going to be very dangerous.”

Some roads are already closed, including part of Interstate 90 near the Pennsylvania border.

The Buffalo Bills play Sunday night, but fans will have to deal with a lot of snow. The county says there could be 20 to 30 inches of snow at the stadium before the game starts. The team is ready to clear the snow, but it will still be hard to get to the game.

“It’s going to be cold, too,” Poloncarz said. “Fans should bundle up and be ready for wind chills in the teens.”

Poloncarz added, “Western New Yorkers know how to handle snow. “We’ll get through this if we’re careful.”