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.

A state of emergency has been declared in the states of Kentucky and Virginia, as well as parts of the US unaccustomed to the cold.