Tropical Storm Isaac is forecast to become a tropical depression by Thursday night, the US National Hurricane Center said in its latest bulletin.
"Isaac continues to produce heavy rains and severe weather as it moves farther inland over Louisiana. Water levels remain high along the northern Gulf Coast," it said.
The center of Isaac will move farther inland over Louisiana today and move over southern Arkansas tonight or early Friday, the NHC said.
Isaac is packing maximum sustained winds near 85 km/h with higher gusts, with the strongest winds are primarily occurring over water or near the coast.