Freezing rain, snow, ice and thunderstorms were wreaking havoc for millions of holiday travelers from the Louisiana Gulf Coast to eastern Canada early on Sunday, as a huge and deadly storm system moved east in time for Christmas.
"This is a particularly strong storm with very warm, near record-breaking temperatures in the East and very cold air in the Midwest, and that contrast is the sort of conditions that are favorable for not only winter weather but also tornadoes," National Weather Service meteorologist Ed Danaher told Reuters.
The bad weather was complicating travel for the 95 million people that travel agency AAA estimates will fly or drive for the holiday.
Advertise | AdChoices
“We’ve had pretty poor weather conditions two weeks in a row leading up to Christmas,” Christopher Dolce, a meteorologist at the Weather Channel. “There’s been a considerable amount of winter storm activity all the way back to the days before Thanksgiving and a lot of travel woes continuing into December.”
Nearly 2,300 flights had been delayed and 433 cancelled across the country on Sunday, according to aviation tracking website FlightAware.com at 5:30 a.m. ET. Some 11,300 flights were delayed on Saturday and 767 were cancelled, according to the website.
Many of these flights were in or out of major hubs like Houston's Bush International, Chicago's O'Hare Airport, Dallas/Fort Worth and Denver International.
Get the latest weather news and your local forecast
The news wasn't good for drivers either.
Darren Hall of Raymore, Mo., told The Associated Press that he normally drives to St. Louis for the holiday, but decided not to risk it this time around.
"You don't have to deal with all the roads. It's safer, less hassle," the 45-year-old said as he waited for a train at Kansas City's Union Station.
Meanwhile, a “significant” ice storm looked set to hit New York State, Vermont, New Hampshire, and central Maine, while a cold front was bringing heavy rains to the Gulf Coast and Mid-Atlantic states, according to the National Weather Service.
Balmy, unseasonable weather was expected ahead of the front, with much of the East Coast seeing highs in the 70s along with high humidity.
“A reality check is coming with much cooler weather arriving by Tuesday and for Christmas Day,” the service warned.
Thirteen states were under flood watches and warnings, with severe weather expected from east Texas through Louisiana, Mississippi, Tennessee and southern Ohio. Three to six inches of rain were reported in southeast Missouri.
The main tornado threat was in parts of Louisiana, Mississippi and Tennessee, said The Weather Channel's Dolce.
The large storm system surged into the Midwest Friday. On Saturday night, a line of thunderstorms stretched from southern Louisiana to Indiana, and at least two suspected tornadoes hit Arkansas, injuring at least five people. And a man in Rena Lara, Miss., was killed Saturday when wind flipped his mobile home.
Two people died when the car they were driving in struck a fallen tree in the road in Jasper County, Mississippi, county coroner Randy Graham told Reuters.
The system sparked different weather in areas separated by a few hundred miles. While in Oklahoma and eastern Missouri, drivers were forced to navigate icy streets, in Memphis, Tenn., residents strolled around in T-shirts.
NBC News' Daniella Silva and Gil Aegerter, Reuters and The Associated Press contributed to this report.