NASHVILLE // With a rare white Christmas in parts of the US Southeast and snow predicted for Washington, DC, airlines canceled hundreds of flights and urged travelers to rethink their plans, while travel authorities warned of potentially dangerous roads.
After blanketing parts of the Midwest and hampering motorists there on Christmas Eve, the storm dipped south late Friday. Winter weather advisories were in effect Saturday morning from Arkansas to the Carolinas and from West Virginia to central Alabama. Much of North Carolina was under a winter storm warning.
The National Weather Service said the storm could bring more than 5 inches (12.5 centimeters) of snow to the Washington region. Meteorologist Stephen Konarik said the storm could hit the area Sunday morning and end Sunday night or early Monday with the peak period of snowfall Sunday afternoon and early evening.
The wintry weather is the result of a low pressure system moving along the Gulf coast. It is expected to intensify and move northeast on Sunday to the mid-Atlantic states and New England.
The weather service was forecasting possible snow for the New York and Boston areas, starting Sunday and continuing into Sunday night, with overnight temperatures in the 20s Fahrenheit (-6 to -2 Celsius) and wind gusts up to 30 mph (50 kph).
Delta Air Lines spokesman Morgan Durrant said 500 weather-related flight cancellations were planned for Saturday nationwide. That included 300 of the 800 scheduled departures from the Atlanta hub. Durrant said those affected had been notified.
He recommended that passengers not travel by air in the Southeast on Christmas if they can help it.
"Atlanta will see more cancellations (Saturday) than on Sunday," he said. The Mid-Atlantic region could see cancellations Sunday.
Air Tran spokeswoman Judy Graham-Weaver said Friday evening that the carrier had only canceled two Saturday flights and was taking a wait-and-see approach to the storm.
In southern states, many were waiting to see whether they would enjoy a rare white Christmas.
By Saturday morning, 4 to 5 inches (10 to 12.5 centimeters) of snow had fallen over several hours in Bowling Green, Kentucky, according to the Weather Service. Louisville had about an inch (2.5 centimeters).
Louisville last had a snowfall on Christmas in 2002, when a half-inch (1.25 centimeters) fell.
In parts of Tennessee, Georgia and the Carolinas, the snow was likely to be mixed with sleet and rain before turning entirely to snow. Temperatures in Georgia are expected to dip into the 20s F (-2 to -6 C) on Christmas night, possibly leading to slick road conditions.
In Minnesota, the storm brought 6 inches (15 centimeters) of snow Friday to Minneapolis and St. Paul. It pushed the monthly total there to 33.4 inches (84.84 centimeters), topping the previous December record set in 1969.
The snow made traveling tough Friday in northeastern Iowa, where the bulk of the storm hovered. Cedar Rapids received more than 7 inches of snow.
Travelers could see airport screeners taking a closer look at empty insulated beverage containers like thermoses because air carriers were alerted about a potential terror tactic involving them, an administration official said.
The Air Transport Association was expecting 44.3 million people on U.S. flights between Dec. 16 and Jan. 5 - up 3 percent over the same period a year ago but still below pre-recession travel volume. The average ticket price was $421, up by 5 percent.
The AAA predicted overall holiday travel to rise about 3 percent this year, with more than 92 million people planning to go more than 80 kilometers by Jan. 2. More than 90 percent said they would be driving.