Hundreds of thousands of people were without power in Georgia, North Carolina, South Carolina and Florida due to the storm, which was also making air travel extremely difficult in some regions.

Reports suggest that more than a foot of snow had fallen in North Carolina, which has declared a state of emergency, on Sunday morning.
Reports suggest that more than a foot of snow had fallen in North Carolina, which has declared a state of emergency, on Sunday morning. (AP)

Millions of Americans have braced for heavy snow and freezing rain with a major winter storm closing in and knocking power out to an estimated 200,000 people.

The dangerous storm was sweeping through parts of the US Southeast on Sunday, making air travel extremely difficult in some parts of the South. 

Conditions were expected to deteriorate later in the day.

The "strong storm over the Southeast/Southern Appalachians will move northeastward inland from the coast to Southeastern Canada by Tuesday," the National Weather Service (NWS) said on its website.

"The system will produce rain, thunderstorms, snow, and rain/freezing rain from the Lower Mississippi Valley to the Southeast/southern Mid-Atlantic, Sunday," with more damage predicted for Monday, it added.

More than 80 million people fell under the winter weather alerts, US media reported.

READ MORE: US snowstorm halts motorists on impassable Virginia highway

Power, flights disrupted

About 200,000 customers had already lost power in the Southeast, including over 100,000 in Georgia alone, according to the website PowerOutage.

Georgia's Governor Brian Kemp had declared a state of emergency on Friday, and snowplows were at work before noon to clear the roads.

Virginia and North Carolina have also declared a state of emergency.

More than an inch of snow fell per hour in some parts of the Carolinas, Georgia, Tennessee and Virginia, according to the NWS Storm Prediction Center.

More than 1,000 flights at Charlotte Douglas International, the nation’s hardest-hit airport, have been cancelled – more than 80 percent of the airport’s Sunday schedule, according to the flight tracking service flightaware.com. 

Drivers were warned of "hazardous road conditions" and major travel headaches from Arkansas all the way up to the northeastern state of Maine.

The NWS even reported some snow flurries in Pensacola, Florida, while social media users in usually mild Atlanta, Georgia, also reported seeing snow.

The storm is also predicted to cause some coastal flooding, with the NWS warning that winds could near hurricane force on the Atlantic coast.

READ MORE: Federal offices, schools shut as snow storm batters US east

Source: TRTWorld and agencies