Hurricane Dorian spun across the Atlantic Ocean toward Florida on Friday, becoming an even stronger Category 4 storm as residents and tourists alike hunkered down in one of America’s biggest vacation destinations.

Dorian has the potential to put millions of people at risk, along with holiday attractions such as Walt Disney World, the NASA launchpads along the Space Coast, and even President Trump’s Mar-a-Lago resort in Palm Beach.

The Miami-based National Hurricane Center said Dorian was packing maximum sustained winds of 140 mph (225 kph) as it churned an unpredictable path toward Florida.

“Although fluctuations in intensity are possible early next week, Dorian is expected to remain a powerful hurricane during the next few days,” the NHC said in a statement on Friday.

On Florida’s east coast, where Dorian’s winds are expected to quickly gather speed on Monday morning, residents snapped up bottled water, plywood and other supplies as fast as they could be restocked. Some gas stations had run out of fuel.

“They’re buying everything and anything that applies to a hurricane, flashlights, batteries, generators,” said Amber Hunter, 30, assistant manager at Cape Canaveral’s ACE Handiman hardware store.

In the Bahamas, evacuations were already underway, two days before Dorian is expected to bring a life-threatening storm surge forecast at up to 10 to 15 feet (3 to 4.5 metres) to the northwest of the islands.

NHC Director Ken Graham saw a worrying, unpredictable situation for Florida, with the hurricane set to hit land somewhere up its east coast and potentially linger over the state, spinning slowly.

“Slow is not our friend, the longer you keep this around the more rain we get,” Graham said in a Facebook Live video.

‘CATASTROPHIC EVENTS’

It was unclear where the hurricane would hit land, but the results were expected to be devastating: “Big-time impacts, catastrophic events, for some areas 140 mph winds, not a good situation,” said Graham.

Hurricane Dorian approaches the coast of Florida, US in this August 30, 2019 NASA handout satellite image. Image: NASA/Handout via Reuters

Mindful of that warning, Cocoa Beach Mayor Ben Malik was putting up storm shutters on his Florida home on Friday afternoon and worrying about the flooding Dorian could unleash on his barrier island town.

“It’s slowed down, we’re looking at a multiple-day event, we were hoping it would just barrel through and leave,” Malik said of forecasts that Dorian could sit over Florida for up to two days, dumping up to 18 inches (46 cm) of water.

“I’m really worried about the amount of rain we’ll be getting.”

Florida Governor Ron DeSantis urged residents to have in reserve at least a week's worth of food, water and medicine.

President Donald Trump told reporters before leaving for Camp David for the weekend: “We’re thinking about Florida evacuations, but it’s a little bit too soon. We’ll probably make that determination on Sunday.”

But Fort Pierce Mayor Linda Hudson urged its 46,000 residents who planned to evacuate not to delay.

“It’s decision time now. Don’t wait until I-95 north and I-75 north and the turnpike are parking lots,” said Hudson, who experienced two devastating hurricanes in 2004.

Dorian’s course remains unpredictable. One of Florida’s last major hurricanes, 2017’s Irma, swept up the peninsula, instead of hitting the east coast.

Florida residents like Jamison Weeks, general manager at Conchy Joe’s Seafood in Port St Lucie, planned on staying put.

“I’m planning on boarding up my house this evening,” said Weeks. “The mood is a little tense, everybody’s a little nervous and just trying to prepare as best as possible.”

In the Bahamas, Freeport's international airport was set to close on Friday night and not reopen until September 3, amid worries that Dorian will slam tourist hotspots on the archipelago.

Dorian began on Friday over the Atlantic as a Category 2 hurricane on the five-step Saffir-Simpson Wind Scale. By Friday night it was moving at nearly 10 mph (16 kph), giving it time to intensify before making landfall.

Two thousand National Guard troops will have been mobilized for the hurricane by the end of Friday, with 2,000 more joining them on Saturday. Florida officials also were making sure all nursing homes and assisted living facilities had generators.

Only one in five Florida nursing homes plans to rely on deliveries of temporary generators to keep their air conditioners running if Dorian knocks out power, a state agency said on Friday, short of the standard set by a law passed after a dozen people died in a sweltering nursing home after 2017’s Hurricane Irma.

North of Cape Canaveral, the Kennedy Space Center’s 400-foot (122-m) launch tower was dragged inside a towering vehicle assembly building to shelter it from Dorian, a video posted by the National Aeronautics and Space Administration (NASA)-owned space launch center showed.