HOUSTON, Oct. 7 (Xinhua) -- Hurricane Nate made landfall near the mouth of the Mississippi River on the southeastern Louisiana coast Saturday evening, with no casualties in the United States reported yet.

Before making landfall on the U.S. coast, Tropical Storm Nate caused severe flooding in parts of Central America that left at least 22 people dead in Nicaragua, Costa Rica and Honduras.

Nate, which was earlier estimated to make landfall around midnight Saturday, escalated to a Category 1 hurricane late Friday night.

Officials in the U.S. states of Louisiana, Mississippi, Alabama and Florida have declared a state of emergency before Nate's landfall, ordering evacuations and issuing curfews.

Maximum flooding of 7 to 11 feet (2.1 to 3.3 meters) above ground level is expected in parts of southeast Louisiana and along the Mississippi coast, the U.S. National Hurricane Center said.

A storm surge warning is in effect from Grand Isle, Louisiana, to the Okaloosa/Walton county line in Florida.

The highest storm surge is expected Saturday night along the Mississippi coast and southeastern Louisiana coast. The water is forecast to recede Sunday morning as the storm quickly moves inland.