MIAMI, United States (AFP) — Hurricane Hermine churned on a path toward Florida where it is expected to hit land overnight, after forecasters on Thursday upgraded it to hurricane status.

“This is life-threatening. This hurricane is strengthening,” Governor Rick Scott told journalists. “We’re going to see landfall about 2:00 am (0600 GMT).”

Data from an Air Force hurricane hunter plane indicated that maximum sustained winds in Hermine were about 75 miles (120 kilometres) per hour at 1855 GMT, the Miami-based National Hurricane Center said.

That would make it a Category One hurricane on the Saffir-Simpson scale. Hermine is the fourth Atlantic hurricane of 2016.

Hermine was about 85 miles south of Apalachicola and moving about 14 miles per hour.

A hurricane warning was in effect for northern Florida and authorities predicted life-threatening surges and flooding rains.

“Winds are already near tropical storm strength in portions of the warning area, making outside preparations difficult or dangerous,” the NHC said. “Preparations to protect life and property should be rushed to completion.”

Pentagon spokesperson Jeff Davis said 100 Florida National Guard personnel were activated, with 6,000 more on alert in the state and 34,000 members ready to deploy from elsewhere in the US.

President Barack Obama has asked FEMA administrator Craig Fugate to keep him updated on the situation “and to alert him if there are any significant unmet needs,” said White House spokesperson Josh Earnest.

“Local, state and federal officials have been working diligently to prepare for these storms and have resources on hand to respond to them as necessary,” said Earnest.

Scott has declared a state of emergency in 51 counties to free up resources to brace for the storm.

“Anyone in the storm’s path must have ready the resources your families need such as water, flashlights, batteries and medicine,” he said, warning that power could go out for days or even weeks.

The state of Florida has declared mandatory evacuations in the counties of Dixie, Franklin, Taylor, Wakulla and Levy.