Near McNeill, Miss., in the southwestern part of the state, winds from a storm, possibly a tornado, damaged a dozen homes and injured several people, none seriously, said Pearl River County's emergency management agency director, Danny Manley.
Trees fell on a few houses in central Louisiana's Rapides Parish, but there were no injuries reported and crews were cutting trees out of roadways to get to people in their homes, said Sheriff's Lt. Tommy Carnline.
Fog blanketed highways, including arteries in the Atlanta area, where motorists slowed as a precaution. In New Mexico, drivers across the eastern plains had to fight through snow, ice, and low visibility.
At least three tornadoes were reported in Texas, though only one building was damaged, according to the National Weather Service, by early evening. Tornado watches were in effect across southern Louisiana and Mississippi.
Nearly 350 flights nationwide were canceled by the evening, according to the flight tracker FlightAware.com. More than half were canceled into and out of Dallas/Fort Worth International Airport, which received a few inches of snow.
Christmas lights also were knocked out with more than 70,000 people without power in east Texas, Arkansas, Mississippi, and Louisiana.
Blizzard conditions were possible for parts of Illinois, Indiana, and western Kentucky with predictions of 4 to 7 inches of snow.
Some mountainous areas of Arkansas' Ozark Mountains could get up to 10 inches of snow, which would make travel "very hazardous or impossible" in the northern tier of the state from near whiteout conditions, the National Weather Service said.
The holiday may conjure visions of snow and ice, but twisters this time of year are not unheard of. Ten storm systems in the last 50 years have spawned at least one Christmastime tornado with winds of 113 m.p.h. or more in the South, said Chris Vaccaro, a National Weather Service spokesman in Washington, via e-mail.
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.