Three people have already died in Jamaica as it braces for the world's strongest storm this year - and possibly the strongest on record for the island - with US meteorologists warning of "catastrophic and life-threatening" conditions.

With wind speeds of up to 175mph (282km/h), Hurricane Melissa is a category five storm - the maximum strength. It is intensifying and expected to make landfall on the Caribbean island early on Tuesday.

It has been blamed for four deaths in Haiti and the Dominican Republic, in addition to the lives lost in Jamaica.

Experts warn that Melissa's slow pace may mean prolonged torrential rain in some areas, increasing the risk of deadly flooding and landslides.

The latest data from the US-based National Hurricane Center (NHC) shows that in terms of maximum wind and low central pressure, Melissa is the world's strongest storm so far this year.

At its current strength, it would be the strongest hurricane to hit Jamaica since record-keeping began in 1851, CBS, the BBC's US news partner, reported.

Tropical storm conditions are already occurring in Jamaica, and "catastrophic and life-threatening hurricane-force wind conditions are expected to begin Tuesday morning," the latest NHC public advisory update said at 23:00 ET (03:00 GMT) on Monday.

Three "storm-related deaths" were already reported in Jamaica Monday evening ahead of the hurricane's landfall, Jamaica's ministry of health and wellness said on X.

The NHC said Melissa was currently about 140 miles (240km) south-west of the capital Kingston, with sustained winds of 175mph, (280km/h). It was moving "north-northeast" at 2mph (4 km/h).

The update warned that within the eyewall - the inner part of the hurricane next to the eye, where wind speeds are typically the highest - "total structural failure is likely".

It urged extra caution in Jamaica's "higher elevation areas", where wind speeds could be as much as 30% stronger.

NHC director Michael Brennan warned Jamaicans: "Do not venture outside with catastrophic life threatening flash flooding and numerous landslides expected through Tuesday."

He advised not to "go out in the eye as it passes over your area. The forward speed of Melissa is going to increase and the eye is going to start to move very quickly across the island."

Forty inches of rain (100cm) was possible in parts of Jamaica over the next four days, according to the NHC.

"This extreme rainfall potential, owing to the slow motion, is going to create a catastrophic event here for Jamaica," said NHC deputy director Jamie Rhome.

The Jamaican government has ordered evacuations for parts of Kingston. In a BBC interview, Jamaican Education Minister Dana Morris Dixon warned of an impending storm "the likes of which we have never seen".

"We've been having rain all of October. So the ground is already very saturated. And then to take that much rain means we're going to have flooding, extensive flooding and landslides in the mountainous areas," she told BBC Newshour.

The minister added: "We have 881 shelters. We have activated all our shelters. All of them are free.''

A Hurricane Hunter aircraft, which collects data in severe storms and informs forecasts on the pathway and intensity of hurricanes, was forced to abort a mission after experiencing severe turbulence, a spokesperson for the US National Oceanic and Atmospheric Administration told CBS.

Evadney Campbell, a Londoner currently visiting family on Jamaica's north coast, told the BBC: "The house that I am in is hurricane proof. It is built with blocks and steel from top to bottom and is filled with concrete.

"We're checking on neighbours to see if they are OK.

"I am worried about people who live on the lowlands in parts of the south-east. Many do not want to leave their homes as they are worried about looting their houses," Ms Campbell said.

Damian Anderson, a 47-year-old teacher from the mountainous town of Hagley Gap in the south-east, said impassable roads already had cut off his community.

"We can't move. We're scared," he was quoted as saying by Reuters news agency.

Jamaica's Prime Minister Andrew Holness has ordered the immediate evacuation of several vulnerable communities across the island.

In a post on X, he urged "every Jamaican to prepare, stay indoors during the storm, and comply with evacuation orders".

"We will weather this storm and rebuild stronger," he wrote.

"You have been warned. It's now up to you to use that information to make the right decision," he said during a briefing, and told CNN, "I don't believe there is any infrastructure within this region that could withstand a Category 5 storm, so there could be significant dislocation."

In some rural areas, school buses were used to ferry vulnerable people to shelters and across the country.

Later on Tuesday night, hurricane conditions are expected in Cuba, as well as tropical storm conditions in Haiti, according to the NHS report.

The Bahamas will experience hurricane conditions on Wednesday, with tropical storm conditions in the Turks and Caicos Islands on Wednesday.

At least three people are already known to have died and hundreds of homes have been flooded in Haiti as Melissa brought torrential rainfall to the island of Hispaniola.

In the Dominican Republic, located on the eastern side of Hispaniola, one person also died.

Local media identified the victim as a 79-year-old man who had been swept away by floodwaters in the capital, Santo Domingo.

A 13-year-old has also been reported missing after being dragged away by strong currents as he was swimming in the sea.

Several people were rescued after being trapped in their cars by the rising floodwater.

If you are in the region, tell us about your preparations for the hurricane. (BBC)

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