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 light dusting of snow began covering the Buffalo Bills' facility on Friday as the team completed its final practice of the week inside Highmark Stadium.

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.