A “significant tornado outbreak” was expected to hit parts of the South with dangerous winds and hail on Wednesday, the National Weather Service said.
Tornado warnings were in effect across Mississippi and Alabama on Wednesday afternoon, according to Bill Bunting, chief of forecast operations at the service’s Storm Prediction Center. There were already reports of damaged homes in Wayne County, Miss., and wind damage to structures and trees in Sumter County, Ala., on Wednesday.
A “few dozen thunderstorms” were occurring across the southeastern United States, Mr. Bunting said. “We expect them to become stronger and more intense as we move through the next several hours, well into the nighttime hours,” he added.
He said he expected each thunderstorm to produce one tornado. The storms were set to bring winds over 100 miles per hour, as well as hail ranging in size from golf ball to baseball.
The Weather Service issued a “particularly dangerous situation” tornado watch for parts of Louisiana, Arkansas and Mississippi on Wednesday until 7 p.m., indicating “a potential for multiple strong, long-track tornadoes.”
“This event is really just getting started,” Mr. Bunting said, adding, “It’s going to be a long evening.”
With the storms hitting some areas well after dark, “you can’t see storms approaching very effectively,” Mr. Bunting said, advising people to be prepared and take action when warnings are issued and “not wait until they can see the danger.”
“For most areas, there will be more than one round of thunderstorms,” he said. “It’s important not to let your guard down after one storm passes.”
The storms will most likely bring “substantial” power outages, downed trees and flooding, he said, adding that structural damage from the “intense, long-track tornadoes” was perhaps the biggest concern.
As one cluster of storms was hitting Mississippi and Alabama on Wednesday afternoon, a separate line of storms was set to develop over Arkansas and Louisiana later in the evening before moving east — hitting Mississippi and Alabama again.
Parts of Georgia, central Tennessee, North Carolina and South Carolina, as well as southern Ohio and Virginia, could be affected by the storms on Thursday.
People in areas where tornado warnings are issued should shelter on the lowest floor of their homes and cover themselves with a mattress or pillow, as well as a helmet if one is available, to decrease the risk of injury, Mr. Bunting said.