(Updates New York forecast in second paragraph, flight cancellations in fourth, blackout numbers in fifth.)
Feb. 12 (Bloomberg) -- Thousands were without electricity across the South as a powerful winter storm moved across the eastern U.S., snarling ground and air traffic and threatening heavy snow for Northeastern cities including New York.
New York and Washington may get as much as 8 inches (20 centimeters), while Philadelphia is forecast to receive 6 to 10 inches, the National Weather Service said. An inch of ice was possible in parts of Georgia and South Carolina. Winter storm alerts stretched from Arkansas to Maine.
“It looks to be the worst ice storm in Atlanta since 2000, and that one knocked out power to 500,000 people,” said Rob Carolan, owner of Hometown Forecast Services Inc. in Nashua, New Hampshire.
Across the U.S., 3,157 flights were canceled as of 1:42 p.m. today, including two-thirds of all arrivals and departures at Hartsfield-Jackson Atlanta International Airport, said FlightAware, a Houston-based tracking service. An additional 2,620 were scrubbed for tomorrow. Amtrak said it suspended some long-distance train service into the U.S. South. Ten traffic deaths in the region were blamed on the storm, the Associated Press and state officials said.
About 385,000 homes and businesses were blacked out by the storm as of 2 p.m. New York time today, according to utility websites. That included 140,000 customers in Georgia, where Southern Co.’s Georgia Power is the largest utility. Southern’s Alabama Power said it was preparing to send crews to help.
“Possibly historic ice accumulations of over 1 inch of ice will be possible for portions of northern Georgia and South Carolina, with a little over half an inch of ice possible for central North Carolina,” said the U.S. Weather Prediction Center in College Park, Maryland.
A half-inch of ice is all that’s needed to take down power lines, Carolan said.
Georgia Governor Nathan Deal issued a state of emergency for 89 counties, urging residents to stay off the roads. Schools in the Atlanta area were closed through today.
In Atlanta, the city’s usually busy roads were clear and its buses halted because of the storm. The Metropolitan Atlanta Rapid Transit Authority was sending some buses into the streets to act as warming shelters, according to its website.
President Barack Obama declared an emergency for northern Georgia, freeing up federal funds to deal with the aftermath of the storm. Officials in Louisiana, Tennessee, North Carolina, South Carolina, Alabama, Mississippi and Virginia also issued emergency declarations.
The ice storm hit overnight in Louisiana, where 37,400 customers were blacked out today. The storm began with rain that turned to ice, coating trees and power lines, said Robbyn Cooper, a spokesman for utility Cleco Corp. The Pineville, Louisiana-based company expects to restore most power by tomorrow, according to a statement.
Tallulah, Louisiana, in the northern part of the state, received an inch of ice and many areas from Texas to South Carolina got from 1/10 to 1/3 inch with more coming, the weather prediction center said.
As much as 5 inches of snow was reported in parts of Georgia and Alabama, while as much as 10 inches fell in coastal North Carolina, according to the center.
Snow will begin tonight in Washington and overnight in New York, then start in Boston early tomorrow, said Tom Kines, a meteorologist with AccuWeather Inc. in State College, Pennsylvania.
In New York, snow showers will start in the city after midnight and then become heavier throughout the morning, said Joe Pollina, a weather service meteorologist in Upton, New York.
“By the time commute time comes around, we may see some moderate to heavy snow falling across the area,” Pollina said.
Rain and sleet may mix in with the snow throughout the day before changing back to all snow tomorrow, he said. In northern New Jersey, it is possible 10 to 14 inches will fall, with some areas getting more.
Flat roofs, trees and power lines are in danger from new snow dropping on top of any snow left over from last week, Pollina said. On Feb. 3, 8 inches fell in Central Park.
So far this year, the park has received 41.5 inches, or 25.8 inches more than the 30-year average of 15.7, according to weather service data.
The storm’s track will determine how much snow falls across the Northeast, Carolan said. Warmer air near the coast will mean more rain in the mix, holding down snow accumulation.
“The tough thing about these things is to forecast where the rain/snow line sets up, because if you are wrong you are dead,” Carolan said.
Boston may get 2 to 4 inches, the weather service said.
The heaviest snow will probably fall along Interstate 81 in western Virginia, through central Pennsylvania and New York before turning east into northern New England, Kines and Carolan said.
The storm may be the best of the season for the ski areas of northern New England, in time for the February school vacation that begins next week, Carolan said. The area has been on the fringe of many storms this year and has yet to take a direct hit.
--With assistance from Jim Polson in New York; Duane Stanford in Atlanta and Kristen Jensen in Washington. Editors: Charlotte Porter, Richard Stubbe