Isaias, the first hurricane of the Atlantic season, was packing maximum sustained winds of 120 mph (193 kph) and was expected to continue strengthening before reaching the coast. Category 3 storms are considered major hurricanes capable of causing devastating damage, the hurricane center said.
A hurricane warning was in effect from Ocean Springs, Mississippi, to the western Florida Panhandle, with tropical storm warnings stretching from southeastern Louisiana to Aucilla River along Florida's Big Bend.
Coastal communities rushed to complete preparations Friday after days of boarding up windows and filling sandbags. Alabama Governor Kay Ivey ordered non-residents to immediately evacuate Gulf Shores, Orange Beach, and Dauphin Island. Florida Governor Ron DeSantis said about 5,000 National Guard troops were expected to mobilize by Friday. Several counties announced mandatory evacuations for some coastal areas.
Rain began falling along the coast Friday morning, with tropical storm conditions expected by early afternoon. The hurricane center warned that flash flooding and tornadoes were also possible. A storm surge of 5 to 7 feet (1.5 to 2 meters) was forecast, with the deepest water hitting immediate coastal areas.
"Preparations should be rushed to completion as the weather will go downhill quickly today," the hurricane center said in an early morning forecast. "While the storm is not expected to make landfall at peak intensity, it is likely that Isaias will still be a significant hurricane when it reaches the coast."
On Dauphin Island, a barrier island off the Alabama coast, officials encouraged voluntary evacuations, particularly on its western section vulnerable to storm surge. Mayor Jeff Collier told reporters he did not anticipate substantial damage, "but at the same time, these things are very fickle and a little jog here or there, or some last-minute increase in strength — we just have to be prepared for the worst."
Isaias was expected to weaken quickly after landfall and be downgraded to a tropical storm by Saturday afternoon as it moves north and inland along the Alabama-Mississippi line, the center said.