Hurricane Nate weakened to a tropical storm on Sunday ahead of lashing the Mississippi coast with powerful winds and torrential rain.
Streets and highways were left flooded as the fast-moving former hurricane was expected to rapidly weaken as it moved inland.
The fourth major storm to strike the United States in less than two months, Nate killed at least 30 people in Central America before entering the warm waters of the Gulf of Mexico and bearing down on the US South. It has also shut down most oil and gas production in the Gulf.
Nate comes on the heels of three other major storms, Harvey, Irma and Maria, which devastated Texas, Florida and Puerto Rico, respectively. However, with winds of 85 miles per hour (135 km per hour), which make it a Category 1 storm, the weakest in the five-category ranking used by meteorologists, Nate appeared to lack the devastating punch of its predecessors.
Nate was downgraded from a hurricane to a tropical storm early on Sunday and was expected to weaken as it moved further inland, the National Hurricane Center said.
The storm's center will move inland over Mississippi and across the deep south, Tennessee Valley and Central Appalachian Mountains through Monday, the National Hurricane Center said.
Before then storm surges of up to 11 feet (3.4 m) on the Mississippi-Alabama border were possible, the NHC said.
Nate made its initial landfall near the mouth of the Mississippi river on Saturday evening and then made a second landfall early on Sunday near Boloxi, Mississippi, where its 46,000 residents were warned that the highest storm surge could reach 11 to 12 feet. This was the first hurricane to make landfall in the state since Hurricane Katrina in 2005.
John Adams is a Massachusetts native who now lives on Belle Fontaine Beach, a narrow strip of land between the Mississippi Sound and a coastal marsh. Every house on the spit was destroyed by Hurricane Katrina.
"This is my first hurricane," Adams said hours before the storm made landfall. "So far, it's kind of a fizzle."
"This is the worst hurricane that has impacted Mississippi since Hurricane Katrina," Mississippi Emergency Management Director Lee Smithson said Saturday. "Everyone needs to understand that, that this is a significantly dangerous situation."
The storm surge brought flood waters over Highway 90 and up to oceanside casinos in Biloxi, while flood waters swept over streets in communities across Mississippi and Alabama, according to reports on social media.
In Hancock County, Mississippi, northeast of New Orleans, rain and wind were gaining intensity and many streets were washing over. Conditions were likely to worsen in the next few hours, said Brian Adam, director of emergency management for the county.
The county evacuated people from low-lying areas and imposed a curfew.
On Saturday states of emergency were declared in Louisiana, Mississippi and Alabama, as well as in more than two dozen Florida counties.
In Alabama Governor Kay Ivey urged residents in areas facing heavy winds and storm surges to take precautions.
More than 55,000 customers were without power early on Sunday morning, power companies in region reported. Rainfall of 3 to 6 inches (7.6 cm to 15.2 cm), up to a maximum of 10 inches, were expected east of the Mississippi River from the central Gulf Coast into the Deep South, in the eastern Tennessee Valley, and southern Appalachian mountains, the NHC said.
Rainfall in the Ohio Valley and into the central Appalachians could be 2 to 5 inches with a maximum of 7 inches.
New Orleans Mayor Mitch Landrieu lifted a curfew in the city on Saturday evening that was originally scheduled to last until Sunday morning. He said in a statement on social media however, that there was still a serious threat of storm surge outside levee areas.
Florida Governor Rick Scott warned residents of the Panhandle to prepare for Nate's impact.
"Hurricane Nate is expected to bring life-threatening storm surges, strong winds and tornados that could reach across the Panhandle," Scott said. The evacuations affect roughly 100,000 residents in the western Panhandle.
Major shipping ports across the central US Gulf Coast were closed to inbound and outbound traffic on Saturday, as Nate intensified and storm surges of up 11 feet were expected at the mouth of the Mississippi River.
The storm curtailed 92 percent of daily oil production and 77 percent of daily natural gas output in the Gulf of Mexico, more than three times the amount affected by Harvey.
Workers were evacuated from 301 platforms and 13 rigs as of Saturday, said the US Bureau of Safety and Environmental Enforcement.
Before heading north into the Gulf, Nate brushed Mexico's Yucatan peninsula, home to beach resorts such as Cancun and Playa del Carmen, the NHC said.
The storm doused Central America with heavy rains on Thursday, killing at least 16 people in Nicaragua, 10 in Costa Rica, two in Honduras and two in El Salvador.
Thousands were forced to evacuate their homes and Costa Rica's government declared a state of emergency.