Hurricane Zeta is due to make landfall on the U.S. Gulf Coast on Wednesday after bringing heavy rains to Mexico's Yucatan Peninsula.
Forecasters at the U.S. National Hurricane Center said the storm could bring a storm surge of one to three meters as it comes ashore in southeastern Louisiana in the afternoon.
Zeta is also expected to spawn some tornadoes as it pushes into the southeastern United States as well as bring the threat of flooding with its locally heavy rains.
Wednesday morning, the hurricane had maximum sustained winds of about 140 kilometers per hour and some strengthening was expected before it makes landfall.
The governors of Louisiana, Alabama and Mississippi have all declared emergencies in their states to speed aid efforts.
Louisiana has already been hit by two other hurricanes and two tropical storms in 2020.
Zeta is the 27th named storm of this year's Atlantic hurricane season, and it is the 11th storm to reach hurricane strength.