HOLLY SPRINGS, Miss. (AP) -- A storm system forecasters called "particularly dangerous" killed several people and injured many more as it swept across the country Wednesday, and officials were searching for missing residents into the night.

Tornadoes touched down in Indiana and Mississippi, where three were killed. The springlike storms packing strong winds killed two more in Tennessee.

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.

A 7-year-old boy died in Holly Springs, Mississippi, when the storm picked up and tossed the car he was riding in, officials said. Police there said several homes were blown off their foundations.

Close by, in Benton County, Mississippi, two people died and at least two were missing. Crews were searching house-by-house and to make sure residents were accounted for.

In the northwest part of the state, A tornado damaged or destroyed at least 20 homes. Clarksdale Mayor Bill Luckett said the only confirmed casualty was a dog killed by storm debris. Planes at a small airport overturned and an unknown number of people were injured.

Television images showed the tornado appeared to be on the ground for more than 10 minutes. Interstate 55 was closed in both directions as the tornado approached, the Mississippi Highway Patrol said.

After an EF-1 tornado struck the south Indianapolis suburb of Greenwood, television stations showed pictures of damage including a portion of a roof blown off a veterinary office.

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 a "particularly dangerous situation" alert for the first time since June 2014, when two massive EF4 twisters devastated a rural Nebraska town, killing two people.

Elsewhere, skiers on the slopes out West got a fresh taste of powder and most people in the Northeast enjoyed spring-like temperatures as they finished up last-minute Christmas shopping.

"It's too warm for me. I don't like it. I prefer the cold in the winter, in December. Gives you more of that Christmas feel," said Daniel Flores, a concierge from the Bronx, his light jacket zipped open as he shopped in Manhattan with his three children.

Only about half of the nation, mostly in the West, should expect the possibility of a white Christmas.

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.

Twisters hit southeast Mississippi exactly a year ago, killing five people and injuring dozens of others. On Christmas Day in 2012, a storm system spawned several tornadoes, damaging homes from Texas to Alabama.

In Arkansas, Pope County Sheriff Shane Jones said 18-year-old Michaela Remus was killed when a tree crashed into her bedroom. The woman and her 1 ½-year-old sister were sleeping in a bedroom of the house near Atkins about 65 miles northwest of Little Rock, when winds uprooted the tree that crashed through the roof.