By Ian Simpson
(Reuters) - A powerful storm system in the southeastern United States that killed four people, including a woman swept away by flood waters while she called 911, put much of the region under a tornado watch on Monday and delayed hundreds of flights.
The storm front could dump up to an inch (2.5 cm) of rain as far north as New England as it rumbles through the Carolinas and the Middle Atlantic states later on Monday with high winds and thunderstorms, National Weather Service meteorologist Bruce Sullivan said.
"It's just a very strong system," he said. "It's covering a very broad part of the eastern United States, so it's all tied together."
A 52-year-old woman driving in the storm's heavy rains died in Florence, Mississippi, after her car went into a swollen creek at about 4:30 a.m. EDT, said David Ruth, the Rankin County coroner.
The woman called 911 as her car went down, but rescuers were unable to reach her in time in the heavily wooded area, he said.
"It took three hours for the waters to recede enough to find her car," Ruth said.
Another woman was killed overnight in Tallahatchie County when high winds dropped a tree on her home, said Mississippi Emergency Management Agency spokesman Ray Coleman.
About 18,000 homes and businesses were without power in Mississippi, he said.
On Sunday, a tornado flipped over a mobile home near Lafayette, Louisiana, killing a toddler and her mother.
Much of eastern Georgia and western South Carolina were under a tornado watch on Monday, along with the Florida Panhandle. The National Weather Service said there had been 19 reports of tornadoes on Monday.
The bad weather briefly halted flights at Atlanta's Hartsfield-Jackson International Airport, delaying more than 600 flights, according to FlightAware.com. Flights at North Carolina's Charlotte Douglas International Airport also were stopped amid heavy rain, the airport said on Twitter.
Facing the possibility of severe weather, the University of South Carolina postponed a celebration for the school's women's basketball team, which won the national collegiate championship on Sunday.
(Reporting by Ian Simpson in Washington; Editing by Colleen Jenkins and Lisa Shumaker)