MIAMI – Hurricane Dorian blasted across the Bahamas in a record-setting way Sunday, tying an 84-year-old record for the most powerful Atlantic hurricane to come ashore as it continued its unrelenting march toward the U.S. East Coast.

In a statement late Sunday evening, the National Hurricane Center said a "prolonged period of catastrophic winds and storm surge will affect the Abaco Islands and Grand Bahama Island for several more hours."

The National Hurricane Center said the storm was driving sustained winds of 185 mph, with gusts exceeding 220 mph. That tied the Labor Day hurricane of 1935, which tore through the Florida Keys, killing more than 400 people in the days before hurricanes were given names.

Dorian made landfall in Elbow Cay in the Abaco Islands in the northern Bahamas on Sunday afternoon, then made a second landfall near Marsh Harbor on Great Abaco at 2 p.m.

The raging winds tore off roofs, downed power lines and terrified islanders who sought shelter in schools, churches and other shelters. The few videos that have emerged from the northern islands show floodwaters streaming over roads and into homes, as residents plead for help in the middle of the slow-moving storm.

Bahamas Prime Minister Hubert Minnis urged his residents to flee ahead of Dorian's landfall, with officials hiring boats to ferry people to islands farther south. Samuel Butler, the assistant commissioner of the Royal Bahamas Police Force, put it bluntly when talking about those who decided to ride out the storm.

"The end could be fatal," Butler said. "We ask you, we beg you, we plead with you to get to a place of safety."

Flights:600 cancellations and counting

Cruises:Extended vacation for some; delays and cancellations trips for others

Florida arrival

Dorian's slow crawl, estimated at about 1 mph as of early Monday morning, placed it within 115 miles of West Palm Beach, Florida. But forecasters remained unsure of whether, or where, it might make landfall in the U.S. after it makes an expected turn to the north.

The National Hurricane Center warned that life-threatening storm surges and dangerous hurricane-force winds were expected along the east coast of Florida through mid-week.

"Only a slight deviation to the left of the official forecast would bring the core of Dorian near or over the Florida east coast. Residents in these areas should continue to monitor the progress of Dorian and listen to advice given by local emergency officials," it said in a statement at 11:00 p.m. ET on Sunday evening.

Millions of people from South Florida to North Carolina are now on alert and preparing for the worst.

Even if Dorian does not make landfall, the effects will be felt beginning around Monday evening when Florida's Melbourne and Palm Bay areas can expect tropical storm winds, said Ed Rappaport, deputy director at the National Hurricane Center in Miami on Sunday evening.

Tropical storm winds range from 60 to 73 miles per hour with gusts of up to 95 miles per hour, according to the National Weather Service.

Tuesday is when Florida residents on the east coast can expect the worst impacts, Rappaport said.

Areas under a hurricane warning, which on Sunday was from Palm Beach to as far north as Daytona Beach, could still see hurricane-force winds within 36 hours, likely Tuesday, even if the hurricane remains offshore, he said.

Conditions along coastal areas in the southern part of Florida will probably be at their worst on Tuesday, he said.

"As this storm progresses northward, it's quite likely these watches and warnings will have to be extended northward as well," he said Sunday evening.

Evacuations underway

Five Florida counties began evacuations of barrier islands and low-lying areas on Sunday. An additional three are expected to issue evacuation orders on Monday, the state's Division of Emergency Management Director Jared Moskowitz said Sunday night.

“Hurricane Dorian is the strongest storm to ever threaten the state of Florida on the East Coast,” said Moskowitz. “No matter what path this storm takes, our state will be impacted. We will continue to work around the clock to prepare.”

The state is suspending tolls on multiple turnpikes and toll roads in the areas expected to be affected by the hurricane and the evacuations.

Forty-five of Florida's 67 counties announced their school districts would be closed on Tuesday.

Florida Highway Patrol cars will be escorting fuel trucks to ensure that fuel reaches affected areas quickly. Florida, Alabama, Mississippi and Georgia are all waiving hours of service and truck weight for fuel trucks to ensure there will be enough gas available.

Across Florida's border in Georgia, Gov. Brian Kemp on Sunday evening ordered evacuations in six coastal counties east of Interstate 95, the main north-south coastal highway, beginning at noon on Monday.

Still further north, South Carolina Gov. Henry McMaster ordered evacuations of more than 800,000 people starting Monday.

"Every indication that we have has the turn (north) somewhere, it's just a matter of where it's going to be," said Ken Graham, director of the National Hurricane Center in Miami. "But again, with these systems, sometimes they've got a mind of their own."

In Pahokee, Florida, on the east shore of Lake Okeechobee, residents rely on God, shutters and rope to prepare for hurricanes. Mike and Christhie Meister were putting the finishing touches on shutters on their ranch home.

"Some people around here don't take it seriously," Christhie Meister said. "Our biggest concern is the lake. ... I'm freaking out."

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The storm was forecast to continue across Grand Bahama Island on Sunday night and Monday. Storm surge in some areas of the Bahamas was expected to exceed 10 feet, posing "serious threat to both life and property across much of the northern Bahamas," AccuWeather Meteorologist Brandon Buckingham said.

The slow pace of the storm meant some areas could be drenched by up to two feet of rain, adding to the damage, Buckingham said. The Bahamas Labour Ministry warned businesses that "laws regarding price gouging and price hoarding will be scrupulously enforced" over the next several days.

Hurricane Andrew in 1992 is the only Category 5 hurricane ever to pass through the Bahamas, AccuWeather said. "Right now, it's the strongest storm that we've ever recorded in history in modern times in the Bahamas area, so this is a very dangerous situation," Graham said.

Florida Power & Light CEO Eric Silagy warned that "significant power outages" were likely in parts of the state and that "parts of the system will need to be rebuilt."

Rick Knabb, a hurricane expert at The Weather Channel, said the storm is likely to hammer much of the East Coast even if it never makes landfall in the U.S.

"Regardless of the track relative to Florida, the life-threatening winds and water of the hurricane could reach portions of Georgia, South Carolina, and North Carolina later this week," Knabb said.

The National Hurricane Center said Sunday that the storm will bring heavy rains, capable of producing life-threatening flash floods over coastal sections of the southeast and lower mid-Atlantic regions through late this week.

Nothing stronger

Category 5 is the strongest rating and includes only hurricanes with sustained winds of at least 157 mph. Meteorologist Ryan Maue tweeted that, if the scale was extrapolated, Category 6 should start at 182 mph.

Forecasters say Dorian's sustained hurricane winds rank it among the most powerful storms ever recorded in the Atlantic. And it's still strengthening. Philip Klotzbach, a hurricane expert and meteorologist at Colorado State University, said Dorian has the strongest winds this far north in the Atlantic east of Florida on record.

Dorian is powerful but compact. Satellite images portray the hurricane as a relatively small feature, with hurricane-force winds "only" extending out from the center by about 30 miles, while tropical storm-force winds extend outward from the center of the hurricane by about 105 miles, AccuWeather said. That's only about half of what is average for a hurricane.

More:5 things that make Dorian a dangerous hurricane

More:Dorian is a 'major' hurricane. What does this mean?

President Donald Trump visited FEMA headquarters and held a conference call with governors and emergency management officials across the Southeast.

"Americans are strong, determined and resilient and we will support each other," Trump said Sunday. "We will work very hard to minimize the effect of whatever is coming at us."

Bacon reported from McLean, Va. Contributing: Michael Braun and Frank Gluck, Fort Myers (Fla.) News-Press; Amber Roberson, Tallahassee Democrat; Dan DeLuca, Treasure Coast Newspapers; and Elizabeth Weise in San Francisco.