NEW ORLEANS - Gulf Coast residents scrambled to finalize storm preparations as Hurricane Nate raced swiftly over the central Gulf of Mexico on Saturday, gaining added strength as forecasters said it would smash into the U.S. coast during the night.

Louisiana Gov. John Bel Edwards said the storm's eye is expected to make landfall in the area near the mouth of the Mississippi River around 7 p.m., likely as a Category 2 hurricane. He urged residents to make final preparations quickly and stressed that Nate will bring the possibility of storm surge reaching up to 11 feet in some coastal areas and strong winds.

"It's going to hit and move through our area at a relatively fast rate, limiting the amount of time it's going to drop rain," Edwards said. "But this is a very dangerous storm nonetheless."

States of emergency were declared in all three states as Nate -- which has already killed at least 21 people in Central America -- became the latest in a succession of destructive storms this hurricane season.

Forecasters said Nate could dump 3 to 6 inches of rain on the region -- with isolated totals of up to 10 inches.