An advisory from the hurricane center warned that Florida's east-central coast could see a brief tornado sometime Monday afternoon or evening.

A mandatory evacuation of entire South Carolina coast took effect Monday covering about 830,000 people.

Transportation officials reversed all lanes of Interstate 26 from Charleston to head inland earlier than planned after noticing traffic jams from evacuees and vacationers heading home on Labor Day, Gov. Henry McMaster said.

"We can't make everybody happy, but we believe we can keep everyone alive," the governor said.

A few hours later, Georgia's governor, Brian Kemp, ordered mandatory evacuations for that state's Atlantic coast, also starting at midday Monday.

Authorities in Florida ordered mandatory evacuations in some vulnerable coastal areas. North Carolina Gov. Roy Cooper warned his state that it could see heavy rain, winds and floods later in the week.

A hurricane watch was in effect for Florida's East Coast from Deerfield Beach north to South Santee River in South Carolina. A storm surge watch was extended northward to South Santee River in South Carolina. Lake Okeechobee was under a tropical storm watch.

A National Guard official, John Anderson, said many people were complying with the evacuation orders.

"We have not seen much resistance at all," he said in a phone call with reporters. People do understand that Dorian is nothing to mess around with."

AP