Florida officials urged residents in flood-prone coastal communities to get out while they can, ordering evacuations in the face of oncoming Hurricane Irma, which could make landfall Sunday and inflict massive destruction not seen in the state since Hurricane Andrew in 1992.

Hurricanes have lashed South Florida many times, but officials here at the National Hurricane Center said this is shaping up as a once-in-a-generation storm. Forecasters adjusted their advisory late Thursday, projecting Irma to hit the tip of the peninsula, slamming the population centers of South Florida before grinding northward. Hurricane warnings were issued Thursday night for South Florida, with the hurricane center warning that "severe hurricane conditions are expected over portions of the Florida peninsula and the Florida Keys beginning late Saturday."

"This storm has the potential to catastrophically devastate our state," Gov. Rick Scott (R) said in a late-day news briefing. Earlier, he implored people to evacuate. "If you live in any evacuation zones and you're still at home, leave."

[Category 5 Irma stays on perilous path toward Florida]

The state's highways were jammed, gas was scarce, airports were packed and mandatory evacuations began to roll out as the first official hurricane watches were issued for the region. Irma, which has been ravaging the Caribbean islands as it sweeps across the Atlantic, is expected to hit the Florida peninsula with massive storm surges and crippling winds that could affect nearly every metropolitan area in South Florida.

The hurricane center said Thursday afternoon that should Irma's eye move through the center of the state, extreme winds and heavy rains could strafe an area that has millions of residents, from Miami in the east to Naples on the Gulf Coast. Because the eastern side of the storm is the most powerful, numerous cities along the east coast could face extreme conditions.

Miami-Dade County ordered some mandatory evacuations, including for Key Biscayne and Miami Beach, as well as for areas in the southern half of the county that are not protected by barrier islands.

"EVACUATE Miami Beach!" Miami Beach Mayor Philip Levine tweeted, later noting in a news release that once winds top 40 mph, first responders will no longer be dispatched on rescue missions here.

Broward County Mayor Barbara Sharief said evacuations in coastal areas were slated for Thursday. Lee County, on the Gulf Coast, announced Thursday afternoon that all the barrier islands — Sanibel, Captiva, Pine Island, Bonita Beach and Fort Myers Beach — will be under mandatory evacuation orders Friday.

Scott on Thursday night ordered that all state offices, public schools, state colleges and state universities be shut down from Friday through Monday "to ensure we have every space available for sheltering and staging."

Scott has declared a statewide emergency and warned that in addition to potentially forcing large-scale evacuations, Irma could batter areas that last year were flooded by Hurricane Matthew. States of emergency also were declared in Georgia, South Carolina and North Carolina. On Thursday, Georgia Gov. Nathan Deal (R) expanded his declaration from six coastal counties to 30 total counties, issuing a mandatory evacuation for some areas.

[Live updates: Hurricane Irma]

Residents in Savannah, Ga., and Charleston, S.C., began to barricade their homes and flee the coast Thursday. Gov. Henry McMaster (R) warned South Carolinians that a mandatory evacuation of the state's coastline will probably come Saturday morning at 10 a.m. Such an evacuation would come with a reversal of all eastbound lanes of four major roadways, including Interstate 26, which would be converted for a westbound escape from Charleston to Columbia.

Irma on Thursday remained a Category 5 storm, with 175 mph sustained maximum winds, and it is a big storm, with hurricane-force winds extending 60 miles from its center. If the eye does not make landfall, many of the people who haven't evacuated from South Florida could find themselves in hurricane conditions anyway, forecasters say.

Residents are closely watching "the spaghetti" — the dozens of computer models showing possible storm tracks, which vary widely. Computer models say that by Sunday, Irma will make a hard right turn, heading due north into Florida.

The timing of that turn will make all the difference.

If sooner, the storm's center could stay offshore, between Miami and the Bahamas. If later, it could blow through the Florida Keys and come up the southwest side of Florida. Or it could find a middle path straight up through the Everglades and the central spine of the peninsula.

"The wild card here is the turn. Anytime a hurricane makes a turn, it introduces uncertainty," Mark DeMaria, acting deputy director of the National Hurricane Center in Miami, told The Washington Post in the center's headquarters in west Miami-Dade County. DeMaria noted that the computer models have fluctuated modestly, with adjustments in the consensus track of 50 miles or so every day. "But 50 miles onshore versus right of the coast makes a huge difference in impact," he said.

The combination of Florida's geography, the pattern of urban settlement in narrow bands along the coasts and the projected northerly path of the hurricane presents a particularly ominous picture.

"This is a large storm coming from the south," said Dennis Feltgen, spokesman for the hurricane center. "That's the worst-case scenario, because it takes in the entire Gold Coast population, and you have the greatest impact from storm surge from that direction."

Irma's sustained winds were the strongest recorded for an Atlantic hurricane making landfall, tied with the 1935 Florida Keys hurricane.

"Look at the size of this storm," Scott said. "It's powerful and deadly."

Many Floridians were heeding warnings to escape but found themselves sitting in bumper-to-bumper traffic in an effort to reach points north.

A little after 10 a.m. at the National Hotel on Miami Beach, a manager announced in four languages — English, Spanish, Portuguese and French — that guests needed to evacuate because of a city order. At the front desk, guests were given a sheet listing the locations of emergency shelters, none of which were likely to be as nice as the beachfront Art Deco hotel, which was restored a few years ago.

"This morning as I walked to work, I could see the things that could become projectiles," said Natalya Garus, 35, lead concierge at the National. "Street signs. Coconuts. All the trash cans. Smoking stations. All the decorations."

As she spoke, workers used a ladder to dismantle a decorative light fixture hanging over the hotel entrance.

Ruben Vandebosch, 28, and Wim Marten, 26, both of Belgium, and Jim Van Es, 24, of the Netherlands, said their plan is to drive to Atlanta.

"Atlanta has a nice ring to it," Vandebosch said. "It sounds cool."

Among those evacuating: Forty dogs from the Miami-Dade County animal shelter. They're being flown to New York on a private plane owned by a dog lover named Georgina Bloomberg, according to Lauree Simmons, president and founder of the Big Dog Rescue shelter in Loxahatchee, Fla.

Big Dog staff went to Houston after Hurricane Harvey, rescuing 60 dogs from the floodwaters. Those dogs are awaiting adoption at the no-kill shelter. Simmons's 33-acre rescue center has 457 dogs and puppies living in air-conditioned bunkhouses. Staff members were working frenetically Thursday packing up the contents of offices trailers. The dog bunkhouses, meanwhile, are fitted with hurricane impact glass built to withstand 200-mile-an-hour winds, Simmons said.

"The dogs will be very comfortable," she said. "We'll stay here with them through the storm and just keep hoping for the best."



Lauren Jackowiec, adoptions manager for the Jacksonville, Fla., Humane Society, loads crates of cats into the Humane Society's van for an evacuation trip to Sarasota, Fla., on Thursday. (Bob Self/AP)

Popular shopping and dining areas of Fort Lauderdale, north of Miami, were nearly completely empty, the businesses buttoned up with metal curtains and new plywood protecting their front windows.

At the Coral Ridge Yacht Club on the Intracoastal Waterway, General Manager Jay Wallace and Greg Bennett, the club's president, were walking up and down its docks making sure all the vessels, including some 90- and 100-footers valued at $2 million or more, were securely tied down. The club decided Tuesday to cease regular operations — meetings, lunch, dinner and a popular Wednesday happy hour — so that many employees would have time to evacuate.

"Just making sure everything is okay," Wallace said. "We're hoping for the best, but preparing for the worst. You have to."

Less than a mile away, Fort Lauderdale's mostly spotless sandy beaches were virtually deserted, despite the green flags attached to all its lifeguard stands indicating "low hazard" for anyone wanting to take a dip in the ocean. The water was dead calm, not a wave in sight, and the shimmering sand was desolate on a postcard 90-degree day.

In Orlando, four Stetson University students prepared to fly out of town on cheap tickets bought Monday, before prices skyrocketed and seats vanished. One of the students, Draven Shean, is a freshman who has been at school for three weeks and is heading home to Houston, where his family had evacuated in advance of Hurricane Harvey.

"I keep making this joke that God keeps sending hurricanes after me," said Shean, who was wearing a long-sleeved gray shirt with black block letters that said "EVAC." He picked it up two days ago at a thrift store. "I thought it was appropriate."

Others were preparing to ride out the storm. Some were fully prepared, others seemed to have only a vague plan, or none at all.



Shelves that once held bottled water are empty as the city prepares for approaching Hurricane Irma. (Mark Wilson/Getty Images)

At a Costco in Naples, in southwest Florida, almost every morning shopper left the store with a flat or two of bottled water. At Costco's gas station, vehicles jammed the six lanes for fuel. Several customers said the 24 cars waiting at 11 a.m. were nothing compared with the lines during the past two days. Some customers were on their third or fourth gas station seeking to fill up.

"As soon as they said you should consider evacuating, things got way worse," said Michelle Anderson, who was waiting for gas in her Volvo. "I'm from Southern California, where earthquakes get you at random, so the fact that you have the ability to prepare for this is pretty awesome."

Vicki Sargent, a Florida resident since 2003, lives in an RV park in Venice and had driven miles in search of gas Thursday. She said she has to ride out the storm because she takes care of about 70 units owned by people gone for the summer. She won't stay in her own trailer, though.

"Only a fool would do that," she said, saying she'll stay with a friend. "I'm more worried about flooding than the hurricane. We have had rain and were about at saturation point."

Tatiana Wood, 33, a waitress at a restaurant in Miami Beach's Lincoln Road Mall, said she has a friend of a friend who lives in Oklahoma, but she was unclear of the distance or whether she would try to get there.

"If you try to escape, you may lose money," Wood said. "If you stay, you might lose your life."



The National Hurricane Center's acting director, Ed Rappaport, is seen during a televised interview at the National Weather Service's facility in Miami, where they track and predict Hurricane Irma's advance. (Andrew Innerarity/For The Washington Post)

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Sullivan reported from Naples, Fla., and Berman reported from Washington. Kimberly Kindy in Orlando, Lori Rozsa in Palm Beach County, Dustin Waters in Charleston, S.C., and Leonard Shapiro and Perry Stein in Fort Lauderdale contributed to this report.