Florida braces for 'life-threatening' Hurricane Hermine

Tropical Storm Hermine strengthened into a hurricane and steamed toward Florida's Gulf Coast, where people put up shutters, nailed plywood across store windows and braced for the first direct hit on the state from a hurricane in over a decade.

The National Hurricane Centre said the storm's winds reached about 75 mph in the afternoon, just above the 74 mph hurricane threshold.

Hermine was expected to blow ashore late Thursday or early today along the state's Big Bend — the mostly rural and lightly populated corner where the Florida peninsula meets the Panhandle — then drop back down to a tropical storm and push into Georgia, the Carolinas and up the East Coast with the potential for drenching rain and deadly flooding.

Florida Gov Rick Scott warned of the danger of strong storm surge, high winds, downed trees and power outages, and urged people to move to inland shelters if necessary and make sure they have enough food, water and medicine.

"This is a life-threatening situation," Scott said. "It's going to be a lot of risk. Right now, I want everybody to be safe."

Scott added that 6,000 National Guardsmen in Florida are ready to mobilise after the storm passes. The governors of Georgia and North Carolina declared states of emergency.

As of 5 p.m. (local time), Hermine was in the Gulf of Mexico, centred about 85 miles south of Apalachicola, Florida, and was moving northeast at about 14 mph.

Forecasters said it would strengthen slightly before blowing ashore but would still be only a Category 1 hurricane, meaning a wind speed of between 74 and 95 mph.

Projected rainfall ranged up to 10 inches in parts of northern Florida and southern Georgia, with 4 to 10 inches possible along the coasts of Georgia and the Carolinas by Sunday.

Lesser amounts were forecast farther up the Atlantic Coast, because the storm was expected to veer out to sea.

Residents on some islands and other low-lying, flood-prone areas in Florida were urged to clear out. Flooding was expected across a wide swath of the Big Bend, which has a marshy coastline and is made up of mostly rural communities and small towns, where fishing, hunting and camping are mainstays of life.