(Adds details from Georgia storms, flight delays)
CHICAGO, April 5 (Reuters) - A dangerous weather system producing severe thunderstorms was expected to continue rolling through the U.S. Southeast and parts of the Midwest on Wednesday night, bringing the threat of tornadoes, forecasters said.
The region, covering parts of Alabama, Georgia, Kentucky, South Carolina and Tennessee, faced possible development of supercell storms through the evening as very large hail and damaging straight-line winds appeared likely, the National Weather Service said in an advisory.
However, the damage from the storm system appeared to be minimal as of Wednesday evening.
In Sumter County, Georgia, around 145 miles (233 km) south of Atlanta, reports of a massive tornado were inaccurate and just three homes were damaged, said Nigel Poole, the emergency management director for Sumter County.
"We got lucky, we were pretty fortunate," Poole said by telephone.
In Alabama, multiple counties were at risk of storms bringing hail, damaging winds and possible tornadoes until 9 p.m. local time.
"Large hail up to the size of baseballs and damaging winds will continue to be the dominant concerns of these storms," the service said.
The 5.7 million people who live in the Atlanta metro area should expect as much as 2-1/2 inches (6 cm) of rain throughout the day and into the evening, the service said.
The Federal Aviation Administration issued a ground stop at Hartsfield–Jackson Atlanta International Airport, slowing the flow of inbound flights, but lifted the measure on Wednesday afternoon.
Still, the administration reported delays at the airport and others, including at Chicago's O'Hare International.
At one of the country's most prestigious golf tournaments, the Masters, held in eastern Georgia, a curtain-raiser event was called off on Wednesday for the first time in its 57-year history, due to the storm forecast.
Dozens of school districts in Alabama and Georgia canceled classes while Alabama Governor Robert Bentley declared a state of emergency ahead of the storm front.
"Alabama is no stranger to the impact severe weather can have on communities and the devastation that can occur when the weather takes a turn for the worse," Bentley said in a statement.
In Missouri on Tuesday night, a fire department building and elementary school in the town of Goodman, some 300 miles (480 km) southwest of St. Louis, were extensively damaged when a tornado touched down around 7 p.m. local time, Mary Curry, the assistant city clerk, said by telephone.
The storm caused one minor injury, Curry said. (Reporting by Timothy Mclaughlin in Chicago and Brendan O'Brien in Milwaukee, Wisconsin; additional reporting by Bernie Woodall in Fort Lauderdale, Florida; Editing by James Dalgleish and Richard Chang)