Tropical Storm Zeta strengthened to become a Category 1 hurricane on Monday, according to the US National Hurricane Center (NHC).
"Today, I declared a state of emergency in advance of Hurricane #Zeta. Now is the time for all Louisianans to prepare", Edwards said on Twitter on Monday.
The NHC said late on Monday that Zeta was expected to make landfall within hours, over the northern Yucatan Peninsula of Mexico, with hurricane conditions and a dangerous storm surge.
Zeta's northwestward motion is expected to continue for the next day. Zeta is expected to approach the northern Gulf Coast on Wednesday, making landfall in Louisiana on Wednesday night.