'Catastrophic' storm heads South

• More than 2,500 flights have been canceled ahead of the storm


• Five are dead in weather-related incidents in Texas, Mississippi, authorities say


• Up to an inch of ice could coat parts of Georgia, more than a foot of snow in the Carolinas


• Utility executive warns power outages could last days

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Atlanta (CNN) -- The coming hours will tell the story across the Southeast. But no one knows yet if the long-anticipated winter storm will live up to the hype.

Families are snug in their homes after baring grocery store shelves. Road crews are staged along nearly empty highways and electric companies are ready to spring into action when power lines go down. Thousands of flights have been canceled.

But will it be enough?

National Weather Service forecasters say this winter storm -- packed with sleet, snow, rain and especially ice -- is different. They call it a potentially "catastrophic event."

"This is one of Mother Nature's worst kind of storms that can be inflicted on the South," Georgia Gov. Nathan Deal told reporters Tuesday afternoon. "That is ice. It is our biggest enemy."

Make no mistake, this is a beast of a storm system. Winter storm warnings, watches and advisories are in place from Texas to Maine. A separate ice storm warning cuts a swath across Georgia's midsection. Up to an inch of ice could coat trees and power lines.

"Widespread and extended power outages are likely as ice accumulates on trees and power lines and brings them down," the warning says. "Please prepare to be without power in some locations for days and perhaps as long as a week."

The threat is very real for a region virtually shut down two weeks ago by a couple of inches of snow. Accumulations of 3 to 5 inches are expected in metropolitan Atlanta, more in the northern suburbs.

The expectations are worse in northeast Georgia and upstate South Carolina.

Residents of Charlotte, North Carolina, were looking at up to a foot of snow, while mountainous southwestern Virginia also could see up to 14 inches.

Transportation woes

The storm system was taking its toll on travel across the region.

Amtrak suspended some of its rail service in the Northeast, South and Mid-Atlantic regions for Wednesday.

Airlines announced more than 2,500 flight cancellations. The hardest-hit airports were Atlanta and Charlotte, according to Flight Aware.com.

Passengers aren't the only ones stuck. Some Delta employees at Atlanta's Hartsfield-Jackson International Airport slept on planes overnight because there aren't enough hotel rooms for everyone, the airline said.

Road conditions

Georgia's Department of Transportation put crews on 12-hours shifts to salt, sand and scrape the roadways.

Gov. Deal said the state has brought in an additional 180 tons of salt and sand in an effort to keep roadways open, but he urged his citizens not to put themselves "in jeopardy or danger."

And residents seemed to heed his advice. Tuesday's rush hour traffic was extremely light. Traffic clustered around gas stations and grocery stores, with no one wanting to get caught short.

South Carolina Gov. Nikki Haley dispatched additional Highway Patrol officers to help with the expected accidents and stranded motorists on state highways, her office announced.

Deadly toll

So far, at least five deaths have been blamed on the weather, including three people who died when an ambulance driver lost control on an icy patch of road outside of Carlsbad, Texas.

The ambulance slid off the roadway into a ditch, where it rolled over, caught fire and burned, the Texas Department of Public Safety said. A patient, a paramedic and one other passenger were pronounced dead on scene.

"If you get even a tenth of inch of ice on a road, it's like a skating rink," said Kurt Van Speybroeck, a National Weather Service meteorologist in Dallas.

In Mississippi, where the northern part of the state could see up to four inches of snow, authorities blamed two traffic deaths on the storm.

Travelers get another winter wallop

Outage concerns

As storm moved in overnight, Georgia Power, the state's largest utility warned that hundreds of thousands of customers could be out of power "for days" when ice-laden tree limbs crash onto electric lines, if predictions of up to an inch of ice pan out.

"This has the opportunity to be a huge event when you're talking about the amount of ice you're looking at," Aaron Strickland, the emergency operations chief for the power company, told reporters.

The utility staged fleets of trucks across threatened areas, ready to deploy should their fears become a reality. Teams from Florida, Texas and Ohio helped bolster the local line crews. There was expected to be more than enough work to go around.

CNN's Matt Smith, Chelsea J. Carter, Todd Borek and Sarah Aarthun contributed to this report.