NEW ORLEANS (AP) -- Hurricane Nate raced swiftly over the central Gulf of Mexico on Saturday, gaining added strength as forecasters said it would smash into the U.S. Gulf Coast in coming nighttime hours.
Louisiana's governor urged his state's residents to take Nate seriously even before New Orleans and much of his state's fragile coast was placed under a hurricane warning, saying the storm "has the potential to do a lot of damage."
"No one should take this storm lightly. It has already claimed the lives of at least 20 people," Gov. John Bel Edwards said Friday. "We do want people to be very, very cautious and to not take this storm for granted."
The National Hurricane Center in Miami said the core of the Category 1 hurricane was located at 7 a.m. CDT Saturday about 245 miles (395 kilometers) south-southeast of the mouth of the Mississippi River. A hurricane hunter plane found the storm had gained new muscle in recent hours, with top sustained winds rising to at 85 mph (135 kph) amid a threat of some additional strengthening.
A hurricane warning is in effect from Grand Isle, Louisiana, to the Alabama-Florida border and also for metropolitan New Orleans and nearby Lake Pontchartrain. A tropical storm warning extends west of Grand Isle to Morgan City, Louisiana, and around Lake Maurepas and east of the Alabama-Florida border to the Okaloosa-Walton County line in the Florida Panhandle.
States of emergency have been declared in Louisiana, Mississippi and Alabama as Nate — which has already killed at least 21 people in Central America — became the latest in a succession of destructive storms this hurricane season.
In Louisiana, Edwards mobilized 1,300 National Guard troops, with 15 headed to New Orleans to monitor the fragile pumping system there. With forecasts projecting landfall on the central Gulf Coast as a Category 1 hurricane, Edwards urged residents to ready for rainfall, storm surge and severe winds — and to be where they intend to hunker down by "dark on Saturday."
Edwards said forecasts for the fast-moving storm indicate the greatest threats are winds and storm surge. The U.S. National Hurricane Center warned that Nate could raise sea levels by 4 to 7 feet (1.2 to 2.1 meters) from Morgan City, Louisiana, to the Alabama-Florida border. It had already had caused deadly flooding in much of Central America.
A White House statement early Saturday said Louisiana's emergency declaration covering had been approved, adding President Donald Trump authorized the Federal Emergency Management Agency and the Department of Homeland Security to coordinate all federal disaster relief efforts. Such statements are intended to speed aid, save lives and protect public safety and property often even before a storm hits.
In New Orleans, the city's pumping system remains fragile but is working. Two flash floods this summer led to revelations about personnel and equipment problems at the agency that runs the system that drains the city. New Orleans Mayor Mitch Landrieu said 109 of its 120 pumps are functioning, which is 92 percent capacity.
"We are ready for whatever Nate brings our way," Landrieu said of forecasts that Nate could dump 3 to 6 inches (7 to 15 centimeters) of rain on the region — with isolated totals of up to 10 inches (25 centimeters).
Officials ordered the evacuation of part of coastal St. Bernard Parish east of New Orleans ahead of the storm. Earlier Thursday, a voluntary evacuation was called in the barrier island town of Grand Isle south of New Orleans.
On Alabama's Dauphin Island — a barrier island south of Mobile, Alabama — owners hauled boats out of the water ahead of the storm's approach. The major concern was the storm surge was projected to coincide with high tide.
"The west end of the island floods in a good thunderstorm," said Chad Palmer, the owner of FinAtics Inshore Fishing Charters, which operates five charter boats on the barrier island.
In neighboring Mississippi, Gov. Phil Bryant declared a state of emergency in six southernmost counties. State officials warned storm surge was the biggest danger in that state's low-lying coastal areas, as well as high winds that could damage mobile homes. Mississippi's government said 11 evacuation shelters would open away from the immediate coast, with buses available for people who can't drive.
"If you are in an area that has flooded, I would recommend you evacuate that area until the storm has ended and the water has receded for your own personal safety and for the safety of the first responders that will be responding in the event you are trapped," Bryant said.
Parts of Central America were especially hard hit by Nate.
Nicaragua's vice president and spokeswoman, Rosario Murillo, said that at least 11 people had died in that country, including two women and a man who worked for the Health Ministry who were swept away by floodwaters in a canal.
Costa Rica's Judicial Investigation Organism blamed seven deaths in that country on the storm and said 15 people were missing. Flooding drove 5,000 residents into emergency shelters there. Damage caused by the storm prompted Costa Rican officials to postpone a World Cup qualifying soccer match between that country and Honduras, which had been scheduled for Friday night.
In Honduras, there were three dead and three missing, authorities said.