Nasty weather is already complicating travel in parts of the U.S., with forecasts of snow, thunderstorms and more threatening a sloppy Christmas Day from Texas to Florida.
 
In Oklahoma, authorities were already warning would-be travelers to stay home Tuesday as freezing rain and sleet caused a 21-vehicle pileup on Interstate 40 in Oklahoma City.
 
Highway Patrol Trooper Betsy Randolph says several people were taken to hospitals, but she didn't have details on their injuries or conditions.
 
Along the Gulf Coast, residents braced for the possibility of tornadoes and powerful thunderstorms. Quarter-sized hail was reported early Tuesday in western Louisiana, and the weather service said a tornado watch was in effect over parts of southeast and south-central Louisiana until the afternoon.