Heavy rain threat from Tropical Storm Isaac to spread inland during the next few days and water levels remain high along the northern Gulf Coast.
"Even though Isaac is no longer a hurricane, life-threatening hazards from storm surge and inland flooding are still occurring," the U.S National Hurricane Center.
Isaac, which is packing winds of 60 miles per hour (95 km/h), is moving toward the northwest near 6 mph (9 km/h) and is expected to continue in this direction through today, followed by a turn toward the north-northwest by tonight or early Friday, the NHC said.
A dusk-to-dawn curfew is in force in New Orleans tonight after Hurricane Isaac brought flooding and stranded dozens of people.
With mean winds of 80mph and higher gusts, flooding is the biggest threat as Hurricane Isaac pushes up through Louisiana.
New Orleans has been left with localised flooding and 70% of people are without power as Hurricane Isaac passes up Louisiana.