Authorities in Florida’s Okaloosa County have ordered residents and visitors to leave the most vulnerable coastal areas as Hurricane Isaias approaches. The U.S. National Hurricane Center put the storm’s sustained winds at about 85 mph.

The county declared a local state of emergency and activated its second operational response level. Destin officials ordered mandatory evacuations in Zones A and B. Orders also cover vulnerable coastal areas of Fort Walton Beach. The county map groups areas by storm-surge risk, with Zone A covering the most exposed low-lying coast, campgrounds and mobile homes.

Officials designated two initial shelters for evacuees. Davidson Middle School in Crestview is set to serve the general public, people with special needs and families with pets. Animals will be housed in designated areas, but owners will not be allowed to visit them during their stay. People who need special-needs assistance must register in advance with the local health department.

Raider Arena at Northwest Florida State College in Niceville is the second shelter and is intended for the general public. More community centers may open if the initial sites reach capacity. County websites provide an evacuation-zone map, road-closure information and current power-outage reports.

The forecast called for the storm to strengthen and make landfall late Friday or early Saturday near the Florida Panhandle and Alabama. The Associated Press reported that the hurricane threatened dangerous conditions along the Florida Panhandle and in southern Alabama and Mississippi. The National Hurricane Center issued a hurricane warning for parts of northwest Florida and a storm-surge warning.