SAVANNAH, Ga. (AP) — Cities rolled out snow plows that hardly ever leave the garage, a hardware store sold feed scoops for use as snow shovels and alligators in the Okefenokee Swamp burrowed into mud to stay warm Tuesday as a winter storm brought snow, ice and brutal cold to the Deep South, a part of the country more accustomed to hurricanes.
As many as 50 million people across the region could be affected. Shortly after snow began falling in Atlanta, the business hub of the Southeast, traffic came to halt. Interstates were clogged as commuters ended their workday early, and office security guards and doormen took to the streets downtown to try to direct traffic amid a symphony of blaring car horns. At the world’s busiest airport nearby, about 900 flights had been canceled.
In northeastern Alabama, some schools held classes, but quickly had to change course midmorning and dismiss students early because the storm arrived earlier than forecasts predicted. By that time, roads were too icy for travel in some areas and officials said hundreds of students may have to spend the night in classrooms or gyms.
‘‘They have food and we have gas heat and the electricity is on, so that is a possibility,’’ DeKalb County Emergency Management Director Anthony Clifton said. ‘‘We will have a campout before we will send them out into an unsafe situation.’’
Motorists from Texas to Virginia were warned to stay off the roads. Popular warm-weather tourist destinations — Charleston, S.C.; Savannah, Ga.; Pensacola, Fla.; Virginia Beach, Va.; and New Orleans — expected ice and snow over the next two days, rare occurrences in places that seldom even see freezing temperatures for long periods of time.
In Charlotte, N.C., Mike Hammond pushed a grocery cart filled with food to his car and looked at the ominous, gray sky.
‘‘You never know what’s going to happen,’’ he said. ‘‘But I'm making sure I have the staples — and batteries for my flashlights in case something happens to the power. I want to be prepared.’’
Meanwhile, in the Midwest, plummeting temperatures and increasing winds took root for another day even as the storm moved south. Several states in the central US saw schools and other facilities close for a second consecutive day as dangerous wind chills were predicted. In Minnesota, forecasters said wind chills could reach 35 to 50 degrees below zero.
At an Ace Hardware store in the north Georgia town of Cumming, snow shovels were in short supply, but manager Tom Maron said feed scoops — often used in barns — could be substituted.
‘‘We’re fixing to put the ice melt out, and we've got plenty of sand here to mix in,’’ Maron said shortly before dawn.
In Savannah, residents braced for a winter whiplash, barely 24 hours after the coastal city hit a T-shirt friendly 73 degrees. Less than ¼ inch of ice and up to 1 inch of snow was possible in a city that hasn’t seen much snowfall on its manicured squares in the last 25 years.
Savannah had 3.6 inches of snow in December 1989, a dusting of 0.2 inches in February 1996 and 0.9 inches in February 2010.
Jason Deese with the National Weather Service said the snow totals would matter less than the ice potential.
In rural Mississippi, four people died when an early morning fire destroyed a mobile home in Itawamba County, near the Alabama border. Investigators believe a space heater was to blame as temperatures dipped to about 20 degrees overnight. Authorities said the victims ranged in age from 3 months to 35 years old.
Alabama state troopers said a seven-vehicle crash killed two people and injured five others near Wetumpka. It was likely caused by ice on a road, and jackknifed 18-wheelers littered Interstate 65 in central Alabama.
In Montgomery, Bradley Thrift sat in a hotel parking lot letting his truck warm up before heading out with a crew to work on sewers.
‘‘We've got a job to do. We'll just be out in it,’’ said Thrift, wrapped up in a thick coat. ‘‘We'll be safe. When the boss man says that’s it, it’s too slippery, we'll just come back here and wait.’’
At a nearby Publix grocery story, shoppers had cleaned out three shelves of bottled water, and all the boxed fire logs were gone. The milk cabinet had big gaps where rows of gallon jugs were missing.
Forecasters said the Hampton Roads area of Virginia could see a foot of snow. Schools and businesses planned to close early, with the storm expected to further clog an already-busy afternoon commute.
In coastal Charleston, it was a balmy 62 degrees Monday. But the approaching weather led the College of Charleston to cancel classes Tuesday. There was a forecast of rain, and sleet in the late afternoon, with the first snow expected Wednesday morning. The city was expecting up to 3 inches of snow and a ½ inch of ice.
Nationwide, nearly 3,000 flights within, into or out of the U.S. had been cancelled Tuesday, according to statistics from the flight tracking service FlightAware. Only a couple of hundred flights are canceled in the U.S. on a typical day.
At the Okefenokee Swamp in far south Georgia, the alligators were slowing down and burrowing into mud to stay warm.
‘‘Their metabolism slows down so they’re able to not breathe as often, so they don’t have to come to the surface as often,’’ said Susan Heisey, a supervisory ranger at the Okefenokee National Wildlife Refuge. ‘‘These alligators have been on this earth a long time and they've made it through.’’
___Associated Press writers Bruce Smith in Charleston, S.C.; Jay Reeves in Montgomery, Ala.; Ray Henry in Atlanta; Brock Vergakis in Norfolk, Va.; and Janet McConnaughey in New Orleans contributed to this report.