Hurricane Dorian's winds topped Category 2 strength early Friday with the potential to become an "extremely dangerous" Category 4 storm as it barreled toward the southeastern United States, forecasters said.

Dorian's top sustained winds were measured at 110mph late early Friday, putting it near the top of Category 2 on the Saffir-Simpson hurricane wind scale. The National Hurricane Center said it is "expected to become a major hurricane on Friday and remain an extremely dangerous hurricane through the weekend," with top forecast winds of 140 mph.

"It's going to be this big, bad, intense storm — wherever it hits, it's going to do catastrophic wind damage," said Bill Karins, a meteorologist for NBC News.

Karins said late Thursday that forecast tracks suggest that Dorian could approach the Florida coast as slowly as 4 mph to 5 mph.

"That's an extremely slow-moving storm," he said. "Those have multiple high tide-cycle issues, they have rainfall issues, not to mention that those high winds in the same locations over a long period of time have more stress on all of the rooftops and structures and trees."

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Dorian would be the first Category 4 or higher hurricane to make landfall on Florida's east coast since 1992, when Hurricane Andrew was blamed for 44 deaths in the state. Anything at Category 3 or above is considered a major hurricane.

The Navy said it had ordered aircraft at Naval Air Station Jacksonville to evacuate.

Dorian was skirting well east of the Bahamas on Friday morning, but it is expected to approach the northwestern Bahamas Saturday before moving over the region Sunday. A hurricane watch is currently in effect in the northwestern Bahamas.

A storm surge as high as ten to 15 feet is expected to threaten the Northwestern Bahamas, and forecasters are warnings the region will be hit by large and destructive wages. Six to 12 inches of rain are expected, with some areas getting up to 15 inches.

It is too soon to tell exactly when the storm would make its U.S. landfall, but the hurricane center warned of an increasing likelihood of "life-threatening storm surge along portions of the Florida east coast late this weekend or early next week." Six to 12 inches of rain is also expected in the U.S., with some areas getting up to 15 inches. The rainfall may cause flash floods.

Florida Gov. Ron DeSantis expanded a state of emergency to cover all 67 counties.

"As it increases strength, this storm has the potential to severely damage homes, businesses and buildings, which is why all Floridians should remain vigilant," DeSantis said in a statement. "Do not wait until it is too late to make a plan."

President Donald Trump called off his planned trip to Poland over the weekend to oversee the response to Dorian.

In a video posted from the White House on Thursday night, Trump said: "We're ready. We have the best people in the world ready, and they're going to help you."

Trump said that "somebody said" that Dorian would be "bigger or at least as big as Andrew," which caused more than $25 billion in damage in 1992, in addition to killing 44 people.

Andrew was assessed as Category 5 on the Saffir-Simpson Hurricane Wind Scale, with sustained winds of 175 mph. The National Hurricane Center says Dorian might reach Category 4, for which the wind range tops out at 156 mph.

Spooked shoppers jammed stores across Florida's Atlantic coast, stripping their shelves of water, bread and other perishables, while long lines snaked through gas station lanes.

David Sanchez said his local Costco in Fort Myers ran completely out of water on Thursday.

Sanchez, who was filling tanks of gas for generators after he waited his turn, told NBC affiliate WBBH of Fort Myers that he didn't want to have to relive what he and his family went through during Hurricane Irma two years ago.

"We were stuck with no electricity for almost 13 days, so you see I'm going to be prepared," he said.

At a Home Depot in Orlando, hurricane supplies were flying off the shelves, said Joe Cappetta, an employee.

"We may have seen 20 or 30 people asking for hurricane supplies a couple of days ago," Cappetta said. "Now we're in the hundreds."

Boaters, like Curtis Sigretto of Jupiter, near West Palm Beach, also scrambled to find safe havens for their boats on Thursday.

"I have to leave here — my insurance makes me leave," Sigretto told NBC affiliate WPTV of West Palm Beach.

But "I've called all the marinas where I had been hauled out of the water before," he said, and "they don’t have any room."

Mary Radabaugh, manager of Central Marine in Stuart, confirmed that spaces were disappearing swiftly.

"There is not enough land to haul all the boats out in Martin County," Radabaugh told WPTV. "We've had at least 30 looking for a place to put their boats. We cannot accommodate them."

State Emergency Director Jared Moskowitz noted that some forecast tracks indicated that Dorian could veer into the Gulf of Mexico, potentially trapping it along the Panhandle, which he called "the worst-case scenario."

For the first time, emergency managers were formally advising Floridians to have seven days of emergency supplies on hand; previously, they'd said to have three days' worth.

"We have to look at previous storms, right?" Moskowitz told NBC affiliate WJHG of Panama City. "They are getting stronger — the stronger they are, the greater the impact.

"I don't want people to run out of supplies and then, because of power issues or road issues, they can't go get supplies," he said.

The hurricane swept by the Virgin Islands and Puerto Ricoas a Category 1 hurricane on Wednesday with few casualties and little confirmed damage.

The sole confirmed casualty was the death of a man that police in Bayamón, Puerto Rico, confirmed to NBC News was connected to Dorian.

Police told Telemundo PR, the San Juan affiliate of NBC News' Spanish-language network, that the 80-year-old man was climbing a ladder to clear drains at his home in preparation for the storm when he slipped and fell, sustaining a fatal head injury.