Roads became rivers, high-water rescues were underway, and states of emergency were being declared in parts of the Southeast on Sunday after more than a month of rain fell in a day with more on the way.
"The same storm system that linked up with tropical moisture and dumped more than a foot of rain in portions of the south-central United States is crawling eastward," AccuWeather meteorologist Renee Duff said.
Flooding that brought havoc to Oklahoma, Arkansas and other states over the past two weeks was sweeping east, threatening metro areas such as Atlanta; Nashville, Tennessee; Tallahassee, Florida; Columbia, South Carolina; and Charlotte and Raleigh in North Carolina, AccuWeather said.
Thirty miles south of Atlanta, Amy Byars said her neighborhood on Lake Peachtree appeared to have been absorbed into the lake.
"You could've ridden a boat through there," Byars told WSB-TV. "There were ducks in their yards. We got to higher ground because I wasn't going to risk my life."
The rains that rolled into the region will linger at least until Monday. Some areas could get a foot of rain, double or even triple the normal rainfall for June, AccuWeather said.
Parts of central Georgia saw 6 inches of rain in a 24-hour period that ended early Sunday, and up to 2 more inches is possible, the National Weather Service reported.
"Flooding along rivers already out of their banks could become worse," the National Weather Service warned.
Athens, home to the University of Georgia, reported 1.59 inches of rain in one hour; nearly an inch of that fell in 20 minutes. Mayor Kelly Girtz said some residents have emailed him photos of yards that have turned to ponds.
"It is always challenging when so much rain falls so quickly," he told USA TODAY. "Athens is like many towns with older areas supported by infrastructure built prior to contemporary standards, so the volume of water we have experienced has overwhelmed some neighborhoods."
The weather forced some vendors to fold their tents at the city's iconic Hot Corner Celebration and Soul Food Fest, which draws thousands to the historic African American business district. Musical acts were driven indoors at Saturday's fest.