PENSACOLA, FLA.--Authorities ordered nearly 400,000 people to leave the central Gulf Coast region, an area threatened last night by 140-mile-an-hour winds and 15-footrides of hurricane Frederic.

Forecasters warned yesterday that the hurricane would hit the coast somewhere in an area stretching from Pensacola, Fla., to Gulfport, Miss., yesterday night.

The National Hurricane Center in Miami described the storm as "extremely dangerous" and called it one of the deadliest Gulf of Mexico storms of the century.

By noon yesterday, gale force winds up to 75 miles an hour were buffeting the coast near Mobile, Ala., forcing Florida National Guardsmen to close Interstate 10 eastbound into Florida.

In Mississippi, where Red Cross officials said 150,000 people had fled inland, tides six feet above normal hit Jackson County near the Alabama state line. Gov. Cliff Finch authorized the mobilization of the National Guard in Mississippi to assist local officials.

By yesterday afternoon, Frederic was 150 miles south of Pensacola. Forecasters predicted little change in the storm's strength before it reach land. Hurricane warnings were up from Panama City, Fla., to Grad Isle, La.

Florida Gov. Bob Graham yesterday afternoon ordered 1000 National Guardsmen to assist with the evacuation of 150,000 people, and police in Florida said they would use force, if necessary, to move people out of the danger areas.

Forecasters said the storm was approaching a four on the National Hurricane Center's 1-5 rating scale. Camille, which hit the Gulf coast 10 years ago and was one of the two strongest storms this century, was ranked five.