With landfall hours away, Tropical Storm Barry was already lashing the southern coast of Louisiana with wind and heavy rain.
"Dangerous storm surge, heavy rains and wind conditions continuing across the north-central Gulf Coast", the NWS said.
Hurricane Barry is barreling northwest toward Louisiana, packing maximum sustained winds of 75 miles per hour (120 km/h), with heavy rain, storm surges and risky winds expected along the northwest Gulf Coast.
The center is still warning of unsafe, potentially life-threatening storm surges.
Grand Isle, one of the inhabited barrier islands east of the storm's likely path, suffered a full power outage Friday which brought crucial pumping stations to a halt, authorities said.
U.S. President Donald Trump declared a state of emergency in Louisiana on Thursday night, authorizing the Department of Homeland Security and the Federal Emergency Management Agency to coordinate federal funds and resources to help the state cope with the storm and its aftermath. That leaves only 3 or 4 feet for the river to rise before it spills over the levees into neighborhoods. According to the National Hurricane Center, risky storm surges, heavy rains and strong winds are expected across the north-central Gulf Coast.
The months of Midwest flooding adds to the threat from Barry as the Mississippi River is at a level several feet higher than normal.
"Weakening is expected as Barry moves farther inland, and it is forecast to weaken to a tropical depression on Sunday", the NHC said in its latest advisory.
US oil futures hit their highest in over a month on Thursday as a potential hurricane threatened crude output in the Gulf of Mexico and as an incident involving a British tanker in the Middle East highlighted ongoing tensions there.
City officials warned New Orleans residents to secure their homes, stock up on supplies and prepare to huddle indoors.
The Governer took to twitter to say that "No one should take this storm lightly".
Governor John Bel Edwards said New Orleans was well prepared to withstand the storm, but urged vigilance by residents across the state, as authorities called on people to stay off the streets.
In New Orleans, a group of neighbors cleaned out the storm drains on their street.
Gas prices may surge after Hurricane Barry hits the Gulf Coast, where it is now threatening millions.
Some Plaquemines residents were battening down to ride out the storm, despite mandatory evacuation orders. There were predictions of 10 to 20 inches (25 to 50 centimeters) of rain through Sunday across a swath of Louisiana that includes New Orleans and Baton Rouge with some parts of the state possible getting 25 inches (63 centimeters).
Willie Brumfield's home already flooded during heavy rain on Wednesday.
"We can not pump our way out of the water levels ... that are expected to hit the city of New Orleans", she warned. Reinforced and strengthened over the years, they are now about 20 feet to 25 feet (6 to 7 meters) high, and are regularly inspected for seepage or other indications that the structural integrity is compromised.
Almost all businesses in Morgan City, about 85 miles west of New Orleans, were shuttered with the exception of Meche's Donuts Shop.