Hurricane Melissa has intensified into a formidable Category 5 storm as it approaches Jamaica, where meteorologists predict it will cause devastating flooding, trigger landslides, and inflict widespread destruction.

The storm is poised to become the most powerful hurricane to hit the island since record-keeping began in 1851.

Having already claimed six lives in the northern Caribbean, Melissa is charted to make landfall in Jamaica on Tuesday. Following its impact there, it is anticipated to reach Cuba later the same day and subsequently move towards the Bahamas. The storm is not expected to affect the United States.

In Kingston, Jamaica’s capital, 23-year-old hotel receptionist Hanna Mcleod has taken precautionary measures. She secured her home by boarding up the windows and ensured her family, including her husband and brother, are prepared. Stocking up on essentials like canned corned beef and mackerel, she strategically placed candles and flashlights around the house.

“I just told them to keep the door closed,” Mcleod shared.

“I am definitely worried. This is actually the first time I’ll be experiencing this type of hurricane.”

Category 5 is the highest on the Saffir-Simpson hurricane scale, with sustained winds exceeding 250km/h.

Melissa would be the strongest hurricane in recorded history to directly hit the small Caribbean nation, said Jonathan Porter, chief meteorologist at AccuWeather.

A storm surge of up to four metres) was expected along the coast in Kingston, which Porter said is home to critical infrastructure such as Jamaica’s main international airport and power plants.

“This can become a true humanitarian crisis very quickly, and there is likely going to be the need for a lot of international support,” Porter said in a phone interview.

On Monday morning (early Tuesday AEDT), Melissa was centred about 230 kilometres south-west of Kingston and about 530 kilometres south-west of Guantánamo, Cuba, the US National Hurricane Centre in Miami said.

The hurricane had maximum sustained winds of 266km/h and was moving west at 5km/h, the centre said.

Some areas in eastern Jamaica could see up to 101 centimetres of rain while western Haiti could get 40 centimetres, according to the hurricane centre.

“Catastrophic flash flooding and numerous landslides are likely,” it warned.

Mandatory evacuations were ordered in seven flood-prone communities in Jamaica, with buses ferrying people to safe shelter.

But some insisted on staying.

“I hear what they say, but I am not leaving,” said Noel Francis, a 64-year-old fisherman who lives on the beach in the southern town of Old Harbor Bay, where he was born and grew up.

His neighbour, Bruce Dawkins, said he also had no plans to leave his home.

“I am not going anywhere,” Dawkins said, wearing a raincoat and holding a beer in his hand.

The fisherman said he had already secured his vessel and planned to ride out the storm with his friend.

Several towns along Jamaica’s southern coast already reported power outages as winds intensified throughout the night.

“I don’t think the storm will damage my house. My only concern is flooding, because we live near the sea,” said Hyacinth White, 49, who said she had no plans to evacuate to a shelter before the call was disconnected.

A record storm for Jamaica

The slow-moving storm has killed at least three people in Haiti and a fourth person in the Dominican Republic, where another person remains missing.

Two people died in Jamaica over the weekend as they cut trees ahead of the storm, according to the country’s emergency management office.

“I want to urge Jamaicans to take this seriously,” said Desmond McKenzie, deputy chairman of Jamaica’s Disaster Risk Management Council.

“Do not gamble with Melissa. It’s not a safe bet.”

In eastern Cuba, a hurricane warning was in effect for Granma, Santiago de Cuba, Guantánamo and Holguin provinces, while a tropical storm warning was in effect for Las Tunas. Up to 51 centimetres of rain were forecast for parts of Cuba, along with a significant storm surge along the coast.

A tropical storm warning was in effect for Haiti.

Evan Thompson, principal director at Jamaica’s meteorological service, warned that clean-up and damage assessment would be severely delayed because of anticipated landslides, flooding and blocked roads.

A storm of Category four or higher has not made landfall in Jamaica in recent history, Thompson said. Hurricane Gilbert was a Category three storm when it hit the island in 1988. Hurricanes Ivan and Beryl were both Category 4, but they did not make landfall.

The life-threatening storm surge was expected along Jamaica’s southern coast, near and to the east of where Melissa is likely to make landfall, the US centre said.

“Don’t make foolish decisions,” warned Daryl Vaz, Jamaica’s transport minister.

“We are in a very, very serious time over the next few days.”

The storm already has dropped heavy rain on the Dominican Republic, where schools and government offices were ordered to remain closed on Monday in four of nine provinces still under red alert.

Melissa damaged more than 750 homes across the country and displaced more than 3760 people. Floodwaters also have cut access to at least 48 communities, officials said.

In neighbouring Haiti, the storm destroyed crops in three regions, including 15 hectares of maize at a time when at least 5.7 million people, more than half of the country’s population, are experiencing crisis levels of hunger.

“Flooding is obstructing access to farmland and markets, jeopardising harvests and the winter agricultural season,” the UN’s Food and Agriculture Organisation said.

Melissa was expected to keep dumping heavy rain over parts of Haiti as it moves north-east in the coming days.

A hurricane watch was in effect for the southeastern and central Bahamas and for the Turks and Caicos Islands.