MELBOURNE, Fla. — As a strengthening Hurricane Matthew barrelled toward a Florida landfall late Thursday, Gov. Rick Scott issued a stern warning to 1.5 million residents and tourists along the coast to get out now: "This storm will kill you."

He said any who defied warnings faced life-threatening winds as strong as 150 mph, storm surges up to 9 feet and and widespread power outages.

"Evacuate, evacuate, evacuate," a grim Scott said at a briefing flanked by emergency staff. He said he had added 1,000 National Guard troops to the 2,500 troops already deployed.

While the storm's exact track could vary slightly as it locks into its final path in the sweep up from the Caribbean, Scott said Florida "must prepare for a direct hit."

"This storm will kill you," he said. "Time is running out. We don't have much time left."

As of 8 a.m. ET Thursday, the storm was centered about 215 miles southeast of West Palm Beach, Florida and moving northwest toward the state at 12 mph, according to the U.S. National Hurricane Center. Forecasters say the first outer rain bands from Hurricane Matthew have already begun to approach Florida as the big storm crosses the Bahamas toward the state.

Scott has already asked President Obama to declare a pre-landfall emergency and canceled tolls in the affected areas, including the entire Florida Turnpike, Alligator Alley, Central Florida Expressway Authority and the Miami-Dade Expressway Authority, to help speed evaucation.

There were 58 American Red Cross shelters open around the state by Wednesday night. Another 58 were expected to open Thursday. Florida Division of Emergency Management staffers spent Wednesday night finding ways to staff shelters, particularly in Brevard County.

At Miami International Airport, 341 arrivals and 305 departures — or about 90 percent of the daily flight schedule — had been cancelled by mid-morning.

While many motorists jammed highways along the coast, others took their departure in stride.

Along A1A Highway, Paul MacDonald took one last walk with his wife and daughter before they closed up their house on Delray Beach to ride out the storm.

While the storm clouds looked ominous and the forecast called for widespread destruction along their beloved coastline, the Detroit native said it could be worse. "It still beats the snow," he said.

The governors of South Carolina and North Carolina have also declared states of emergency along the coast in anticipation of high-winds and life-threatening storm surges as high as 9 feet in some areas. In Charleston, city officials say the city has run out of sandbags after distributing 15,000 — more than for any other storm.

Gov. Nikki Haley urged residents to get at least 100 miles from the shore, reminding residents who've decided to stay that they could be putting the lives of law enforcement and emergency responders in danger, not just their own.

Roughly 250,000 residents and tourists fled South Carolina's Lowcountry by Wednesday evening ahead of the approaching storm. At least as many more are expected to evacuate Thursday.

Authorities say a motorist in South Carolina was shot and wounded by deputies during an altercation over a Hurricane Matthew evacuation route, the Associated Press reports.

Berkeley County Sheriff Duane Lewis says a motorist knocked down some traffic cones at a check point in Moncks Corner and sped off.

The sheriff says when deputies finally caught up with the driver a few miles away he pointed a gun at deputies and started shooting. The sheriff says the deputies shot back, wounding the man who was taken to the hospital. His name and condition were not immediately released. No deputies were wounded.

The hurricane, which swept northward through the Caribbean, has left at least 16 people dead. Officials in Haiti raised the death toll to 10 and the number is expected to further increase as aid workers reach remote areas. The storm also pounded parts of Jamaica, the Dominican Republic and Cuba.

The Category 3 storm is forecast to straddle Florida's coastline late Thursday into early Friday. The center is projected to scrape Brevard County's with hurricane-force winds that can down trees and scatter debris over a wide area to communities through Friday evening.

Gallop reporting for Florida Today, Brett Blackledge reporting from Tallahassee for The Naples Daily News; Stanglin reporting from McLean, Va. Contributing: Alan Gomez in Miami, Jane Onyanga-Omara in London, Elizabeth LaFleur in Greenville, S.C. and John Bacon in McLean, Va.