NEW ORLEANS - 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.
Please plan now for how you will receive a severe weather warning, and know where you will go when it is issued. It only takes a few minutes, and it will help everyone have a safe Christmas," said Mississippi Gov. Phil Bryant.
In Alabama, the director of the Emergency Management Agency, Art Faulkner, said he was briefing both local officials and Gov. Robert Bentley on plans for dealing with a possible outbreak.
Forecasters said storms would begin near the coast and spread north through the day, bringing with them the chances of storms, particularly in central and southwest Alabama. No day is good for severe weather, but Faulkner said Christmas adds extra challenges because people are visiting unfamiliar areas. Also, people are more tuned in to holiday festivities than their weather radio on a day when thoughts typically turn more toward the possibility of snow than twisters, he said.
"We are trying to get the word out through our media partners and through social media that people need to be prepared," Faulkner said
Meteorologists also recommended getting yards ready Monday, bringing indoors or securing Christmas decorations, lawn furniture and anything else that high winds might rip away or slam into a building or car.
"Make sure they're all stable and secure -- that there's not going to be any loose wires blowing around and stuff like that," or bring them inside, said Joe Rua, with the National Weather Service in Lake Charles, where storms were expected to roar in from Texas after midnight.
In the New Orleans suburb of Metairie, Timothy J. Babin said the 10 or so wire Christmas sculptures in his yard and more than 180 plastic figures in his mother's yard are staked down.
Dozens of toy soldiers, a nativity scene, Santa and nine reindeer (don't forget Rudolph), angels, snowmen and Santa Clauses fill the yard of his mother, Joy Babin.
"From a wind standpoint, we should be fine unless we're talking 70, 80, 90 miles an hour," Timothy Babin said.
On Christmas Eve, more than 100 log teepees for annual bonfires are set up along the Mississippi River in St. James Parish, which is a bit more than halfway from New Orleans to Baton Rouge, and about 20 in St. John the Baptist Parish, its downriver neighbor, parish officials said. Most are 20 feet tall, the legal limit.
Fire chiefs and other officials in both parishes decided to go ahead with the bonfires after an afternoon conference call with the National Weather Service.
The bad weather was expected from a storm front moving from the West Coast crashing into a cold front, said weather service meteorologist Bob Wagner of Slidell.
"There's going to be a lot of turning in the atmosphere," he said.
In California, after a brief reprieve across the northern half of the state on Monday, wet weather was expected to make another appearance on Christmas. Flooding and snarled holiday traffic were also expected in Southern California.
Ten storm systems in the last 50 years have spawned at least one Christmastime tornado with winds of 113 mph or more (F-2) in the South, Chris Vaccaro, a National Weather Service spokesman in Washington, said in an email. The most lethal were the storms of Dec. 24-26, 1982, when 29 tornadoes in Oklahoma, Missouri, Arkansas, Tennessee and Mississippi killed three people and injured 32; and those of Dec. 24-25, 1964, when two people were killed and about 30 people injured by 14 tornadoes in seven states.
Farther north, some mountainous areas of Arkansas' Ozark Mountains could see up to 10 inches of snow, the weather service said Monday. Precipitation is expected to begin as a mix of rain and sleet early Tuesday in western Oklahoma before changing to snow as the storm pushes eastward during the day. The weather service warned that travel could be "very hazardous or impossible" in northern Arkansas, where 4 to 6 inches of snow was predicted.