Tropical Storm Lee knocked out power early on Saturday for more than 38,000 customers, primarily in the New Orleans area, said a utility company that provides power for most of Louisiana.
Outages are expected to increase as the storm moves ashore, Entergy said on its website.
The slow-moving Tropical Storm Lee is predicted to reach the Louisiana coast later on Saturday and deluge the area with rain.
The utility company said flooded roadways could hamper travel and delay workers in getting power restored.
With safety the highest priority, our workers cannot begin restoration until winds fall to a safe level, the company said.