Major winter storm blasts much of U.S. with intense blizzard conditions causing flights disruptions

Tens of millions of Americans are bracing for a massive winter storm Sunday, which is forecast to bring the heaviest snowfall and coldest temperatures to parts of the country in over a decade. The polar vortex has already prompted states of emergency in the Plains, with the storm set to move east and flight disruptions are already underway. NBC News' Maggie Vespa, Aaron Gilchrist and Angie Lassman has the latest.