Storm is predicted to move west and towards the US mainland later on Monday after spending the day over Grand Bahama island

Millions of coastal US residents from south Florida to the Carolinas were evacuating inland on Monday as Hurricane Dorian – a category 5 monster storm with gusts above 200mph – continued to tear apart the northern islands of the Bahamas.

Dorian, the most powerful cyclone to strike the Caribbean in modern times, was predicted to start moving west and towards the US mainland later on Monday after spending the day parked over Grand Bahama island, scouring it with devastating wind and rain.

Q&A Are hurricanes getting stronger? Show Hide 2019 is the fourth year running that category 5 hurricanes have formed over the Atlantic Ocean. While the overall number of hurricanes has remained roughly the same in recent decades, there is evidence they are intensifying more quickly, resulting in a greater number of the most severe category 4 and 5 storms. The proportion of tropical storms that rapidly strengthen into powerful hurricanes has tripled over the past 30 years, according to recent research. A swift increase in pace over a 24-hour period makes hurricanes less predictable, despite improving hurricane forecasting systems, and they are more likely to cause widespread damage. There is growing evidence that the warming of the atmosphere and upper ocean, due to human activity such as burning fossil fuels, is making conditions ripe for fiercer, more destructive hurricanes. Climate breakdown is tinkering with hurricanes in a variety of ways. More moisture in the air means more rain, while storms are intensifying more quickly but often stalling once they hit land, resulting in torrential downpours that cause horrendous flooding.

Rising sea levels are aiding storm surges whipped up by hurricanes – one study found that Hurricane Sandy in 2012 probably would not have inundated lower Manhattan if it occurred a century previously. According to the UN’s Intergovernmental Panel on Climate Change, the maximum intensity of hurricanes will increase by about 5% this century. The expanding band of warmth around the planet’s tropical midriff also means a larger area for hurricanes to develop, resulting in fierce storms further north than before, such as Hurricane Florence. In the Pacific, this change means the focal point of typhoons is switching from the Philippines towards Japan. Oliver Milman

Officials said the storm was continuing to cause terrible damage in the Bahamas, where it made landfall at lunchtime on Sunday, its sustained 175mph winds tearing apart buildings and ripping off roofs, and destroying or severely damaging at least 13,000 homes, according to the Red Cross.

The hurricane, which brought “catastrophic winds” and a storm surge above 20ft to the Caribbean island nation, also claimed its first recorded fatality, an eight-year-old boy who drowned on Abaco Island.

Mandatory evacuation orders were issued in the US ahead of Dorian’s expected midweek march up the east coast, with National Hurricane Center experts warning of “life-threatening storm surges and dangerous hurricane force winds” even if it follows its forecast track of remaining out at sea.

“It is still possible for the hurricane to deviate from this forecast and move very near or over the coast,” Richard Pasch, a senior hurricane expert at the NHC, said.

In South Carolina, Governor Henry McMaster announced the evacuation of eight coastal counties, affecting more than 800,000 residents, adding to earlier orders issued for large numbers of counties along the coasts of central and north Florida and Georgia.

Rick Scott, the former Florida governor and now a Republican US senator for the state, said that even storm surges of seven feet that are predicted to affect the state’s east coast, whether the hurricane makes landfall there or not, were almost unprecedented.

He was concerned that people were not taking the storm seriously and that they should evacuate, where recommended, and prepare elsewhere.

“I want everyone to stay alive … this is not the time to take a chance … I do not want to lose anyone [in Florida] and it’s the same in Georgia and the Carolinas,” he told CNN.

First reported death as category 5 Hurricane Dorian pounds Bahamas – live updates Read more

Later on Sunday, on Great Abaco Island in the Bahamas, footage emerged of floodwaters reaching halfway up the sides of family homes with parts of the roofs torn off. The island chain’s homes are built to withstand winds of at least 150mph (241km/h). Americans should “pray for the people in the Bahamas”, Donald Trump said from Washington as south-eastern US states looked on nervously.

Play Video 1:25 Hurricane Dorian wreaks havoc on Bahamas as 'catastrophic' Category 5 storm – video

The Bahamian prime minister, Hubert Minnis, said in a nationally televised news conference that a “monster storm” was battering the region. “This will put us to a test that we’ve never confronted before,” he said. “This is probably the most sad and worst day of my life to address the Bahamian people. I just want to say as a physician I’ve been trained to withstand many things, but never anything like this.”

The National Hurricane Center (NHC) in Miami said Dorian made a second landfall at 2pm ET (1800 GMT) on Sunday, hitting Great Abaco island with large waves and winds of 185mph with higher gusts. That was tied for the strongest Atlantic hurricane landfall on record, with the 1935 Labor Day hurricane.

As hundreds hunkered down in schools, churches and other shelters, Bahamian authorities made a last-minute plea for those in low-lying areas to evacuate. Reporters in the Bahamas said hundreds of residents of lower-lying islands, including Grand Cay and Sweeting Cay, had ignored mandatory orders to go.

“Once the winds get to a certain strength we’re not going to to be able to respond,” Don Cornish, head of the Bahamas national emergency management agency, warned in a pre-storm briefing. “We may not have the resources to come after persons who are in harm’s way.”

On Monday, the storm, which had been moving west at 8mph, was basically stalled over the islands.

“It’s going to be really, really bad for the Bahamas,” a Colorado State University hurricane researcher, Phil Klotzbach, told the Associated Press, adding: “Abaco is going to get wiped.”

Floridians not fazed as Hurricane Dorian’s path keeps state guessing Read more

On Sunday morning, a significant change to the forecast by NHC experts brought the cyclone much closer to Florida’s south-eastern coast by Monday and Tuesday, prompting new hurricane and tropical storm force watches from just north of Miami to Sebastian inlet, 100 miles north of West Palm Beach. Dorian’s predicted path would then take it north, skirting the US coast towards Georgia and the Carolinas.

SC Governor Press (@scgovernorpress) Gov. Henry McMaster Orders Mandatory Evacuations for Coastal Counties Effective Tomorrow, September 2 at Noon

| Governor Also Ordered School and State Government Office Closures in Coastal Counties https://t.co/yzHoBtyLi6

The increasing strength of the storm makes this the fourth consecutive year that at least one Atlantic cyclone has reached category 5, according to the NHC. Hurricane Matthew in 2016 followed a similar offshore track to Dorian’s expected path yet still caused hundreds of billions of dollars in damage and 47 deaths in the US from wind, storm surge and significant inland flooding.

In 2017 Irma and Maria tore through the Caribbean, the latter blamed for more than 3,000 deaths in Puerto Rico, and last year Hurricane Michael wrecked areas of the Florida Panhandle that are still struggling to recover.

Facebook Twitter Pinterest Boats are seen tied up in preparation for the approach of Hurricane Dorian in Nassau, Bahamas. Photograph: Lucy Worboys/AFP/Getty Images

The Associated Press contributed to this report