Storm Francine barreled across the U.S. South on Thursday, pounding the region with heavy rains and gusty winds while causing widespread power outages for hundreds of thousands of homes and businesses.

It had weakened from a Category 2 hurricane to a tropical depression as it moved northeastward over central Mississippi, but still packed winds of 35 miles per hour (55 km per hour) and threatened areas with dangerous storm surges early on Thursday, the National Hurricane Center said in an advisory.

It was expected to weaken further and become a post-tropical cyclone later in the day, the center added.

In the low-lying, coastal Louisiana city of Houma in Terrebonne Parish, where the storm made landfall on Wednesday evening with winds near 100 mph (160 kph), Christine Bundy, 72, was hooking up a new generator she'd just bought.

"A Cat. 2 is nothing," she told Reuters by telephone on Thursday. "This house has been through every storm since 1975."

It took the deadly hurricane Ida, a Category 4 storm that hit Louisiana in 2021, to earn Bundy's respect and fear.

"Ida took our roof off, tore up the fence and everything," she said. "With this one, we're just cleaning up a little."

Heavy rains were expected throughout the day in Louisiana, Mississippi, Alabama and the Florida panhandle after many spots were inundated with downpours for hours. In all, some spots could see as much as 12 inches (30 cm) of rain before the storm completely subsides, the National Weather Service said.

Government offices, schools and libraries were closed throughout the region as widespread flooding was reported.

“Our drainage system just couldn’t keep up,” said Jennifer Van Vrancken, a councilwoman in Jefferson Parish, which encompasses part of the New Orleans metropolitan area. “This will be a flood where people remember getting water inside their homes.”

The storm left more than 400,000 homes and businesses without power, and dozens of people had to be rescued from floodwaters across the three-state region.

Just to the south of New Orleans in Lafourche Parish, more than two dozen people, including small children, were rescued from rising flood waters on Wednesday evening, the local sheriff's office said online.

New Orleans' iconic French Quarter neighborhood, known for its tourist bars and restaurants, was locked down on Wednesday with a noticeable police presence and very few pedestrians.

Louisiana Governor Jeff Landry and President Joe Biden each declared a state of emergency in anticipation of the storm, freeing up emergency management resources and potential financial aid in the event of serious damage.

In Dulac, Louisiana, a coastal fishing community 70 miles (110 km) southwest of New Orleans, fisherman Barry Rogers rode out the storm on his 80-foot-long (24-meter-long) shrimp boat rather than in his home.

"It was a lot worse than the weatherman said it was going to be," said Rogers. "It moved pretty good."