Tens of millions of Americans braced Sunday for a massive winter storm, expected to bring the heaviest snowfall and coldest temperatures in over a decade to parts of the country.

Blizzard and winter storm conditions blasted the Midwest early Sunday, as a massive weather system began tracking eastward across the United States, with authorities warning of some of the heaviest snowfalls in a decade and severe impact on transport.

The first significant winter storm of the year is endangering a 2,100-mile swath of the country from the Northwest and Plains through the mid-Atlantic and East Coast, bringing a multitude of life-threatening hazards across major metropolitan areas.