More than 4 million people across five states were under winter storm alerts on Sunday as heavy lake-effect snow continued to bury the Great Lakes region, prompting emergency declarations and the deployment of National Guard troops to rescue stranded motorists.

Forecasters warned that some areas would be “paralyzed” by the storm. Nearly three feet of snow had already accumulated in Perrysburg, N.Y., about 30 miles south of Buffalo.

In Erie County, Ohio, a lake-effect snow warning is in place until 7 p.m. on Tuesday. Between 10 and 20 inches of heavy snow accumulations are expected in the north of the county, while between 12 and 24 inches are expected in the south.

Lake effect snow is slamming the Great Lakes, with seven states from Wisconsin to New York under snow alerts on Monday.

The storm dumped several feet of snow and disrupted post-Thanksgiving travel in the Great Lakes states and New York. More snow is expected in the coming days.

Pounding snow and bitter cold continued their assault on parts of the U.S. Copenhagen, N.Y., 80 miles north of Syracuse, reported 58.8 inches of snow.

As biting cold temperatures sweep across a large swath of the US, parts of the Great Lakes face more than a foot of additional lake-effect snow through Tuesday – the latest complication for cities already blanketed by snowfall amid post-Thanksgiving travel.