As blizzard conditions impacted parts of the Midwest, two Southern California coastal locations registered a national high temperature of 94.
A foot of snow, wind gusts up to 65 mph and tornadoes are all possible in the Christmas Eve storm, forecasters said.
The storm is expected to bring blizzard conditions to the Plains and the upper Midwest and severe thunderstorms across the Gulf Coast.
A winter storm will sweep across the nation starting Wednesday, bringing snow to parts of the Midwest and the Northeast, heavy rain to the Gulf Coast and gusty winds to the East Coast through Christmas Day.
As of Sunday, 132 avalanches had been reported, and Colorado’s snowpack is said to be the weakest it has been since 2012.
The impacts of the two storms are "devastating," the U.N. report says. At the humanitarian level, more than 4 million people are affected, with 2.5 million in need.
As millions dig out from under at least a foot of snow after a powerful nor'easter, could more wintry weather be on the horizon for the holiday week?
Kevin Kresen was stranded under snow for 10 hours in Owego, New York after a plow buried his car.
Tens of thousands were without power and there were hundreds of car accidents due to the storm.
The storm could dump over a foot of snow in parts of Pennsylvania, New York and elsewhere; wintry conditions have begun in North Carolina and Virginia.
More than 60 million people were under winter alerts, with forecasts of snow and wind that could snarl travel and knock out power to millions.
Washington, D.C., Philadelphia and New York could get more snow this week than they did all of last winter.
The storm hit most states in New England, bringing wet snow and harsh winds.
Rapidly strengthening storm could produce "impossible travel conditions, whiteout visibilities," and potential power outages, forecasters said.
"Every day, about 20 new people arrive because they lost their land, their homes, and their crops in Honduras and Guatemala," says a shelter director in Tenosique, Mexico.