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

(WJW) — A Lake Effect Snow Warning has been extended until 7 a.m. Tuesday for Ashtabula and Lake Counties. A Lake Effect Snow Warning has also been issued for Cuyahoga and Geauga Counties from 12 p.m. Sunday to 7 a.m. Tuesday.

Lake-effect snow blowing in from the Great Lakes has blanketed parts of Michigan, Ohio, Pennsylvania and New York, stranding hundreds of vehicles on roads and snarling post-Thanksgiving travel plans for millions.

In late fall and winter, lake-effect snow is a common occurrence in the Great Lakes region. "Lake-effect snow occurs when cold air, often originating from Canada, moves across the open waters of the Great Lakes.

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.

Nearly two million people remain under lake-effect snow warnings through early Monday. CNN’s Polo Sandoval reports.