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.

A Lake Effect Snow Warning until 4 a.m. Saturday for Chautauqua and Cattaraugus counties. Another 6 to 12 inches of snow. A Winter Weather Advisory for Niagara, Orleans, Northern Erie, Genesee and Allegany until 4 a.m. Friday. Another 1 to 3 inches of snow.