ATLANTA (AP) — Forecasters warned of a “particularly dangerous situation” as a storm system packing strong winds and heavy rain slammed the nation’s mid-section Wednesday, and officials said they feared Christmas yard decorations would become projectiles.

A tree blew over onto a house in Arkansas, killing an 18-year-old woman and trapping a 1-year-old child inside, authorities said. Rescuers pulled the toddler safely from the home.

The biggest threat for tornadoes was in a region of 3.7 million people in Mississippi, Tennessee and Arkansas and parts of Missouri, Illinois and Kentucky, according to the national Storm Prediction Center in Oklahoma. The center issued its “particularly dangerous situation” alert for the first time since June 2014, when two massive EF4 twisters devastated a rural Nebraska town, killing two people.

The greatest risk for a few “intense, long-tracked tornadoes” will be through Wednesday night.

In parts of Georgia, including Atlanta, a flood watch was posted through Friday evening as more than 4 inches was expected, the National Weather Service said.The threat of severe weather just before Christmas is unusual, but not unprecedented, said Greg Carbin, a meteorologist at the national Storm Prediction Center. On Christmas Day in 2012, a storm system spawned several tornadoes, damaging homes from Texas to Alabama.

Emergency officials in Tennessee worried that powerful winds could turn holiday yard decorations into projectiles, the same way gusts can fling patio furniture in springtime storms, said Marty Clements, director of the Madison County Emergency Management Agency in Jackson, the state’s largest city between Memphis and Nashville.

“If you go through these neighborhoods, there are a lot of people very proud of what they’ve put out and they’ve got stuff everywhere – all these ornaments and deer and everything else,” Clements said. “They’re not manufactured to withstand that kind of wind speed, so they become almost like little missiles.”

Once the strong storms clear out, forecasters say, the high temperature in Atlanta on Christmas Eve is expected to be in the mid-70s. That could break the record for Dec. 24, which is 72 degrees set in 1984, according to weather service records.___

Associated Press writers Alexandra Olson in New York; Claudia Lauer in Little Rock, Arkansas; and Jay Reeves in Birmingham, Alabama, contributed to this report.