Hurricane Melissa has reached Category 5 strength before making landfall late tonight or early tomorrow in Haiti or Jamaica.

The storm will unleash torrential rain and threaten to cause catastrophic flooding in the northern Caribbean,the US National Hurricane Centre said.

Brits on the island have been urged to seek shelter immediately.

Visit our updated article for live tracking of Hurricane Melissa

Where will Hurricane Melissa hit?

‘Conditions (in Jamaica) are going to go down rapidly today,’ Jamie Rhome,the centre’s deputy director,said on Sunday.

‘Be ready to ride this out for several days.’

Melissa has maximum sustained winds of 145mph and is moving west at 5mph,the hurricane centre said.

The storm could drop torrential rains of up to 76cm on Jamaica and southern Haiti,and the Dominican Republic – some areas may see as much as 101cm of rain.

Heavy rain and wind will also likely hit parts of Florida and Cuba.

Kingston locals barricade the doors as they try to wait out the storm (Picture: AFP)

Extensive damage to infrastructure,power and communication outages,and the isolation of communities in Jamaica are expected.

Melissa should be near or over Cuba by late Tuesday,where it could bring up to 30cm of rain,before moving toward the Bahamas later on Wednesday.

Jamaica’s two main airports,the Norman Manley International Airport and the Sangster International Airport in Montego Bay,closed on Sunday.

Winds and waves are already picking up ahead of the storm (Picture: Reuters)

Local officials ordered the evacuation in the seaside community of Old Harbour Bay in the southern parish of St Catherine on Sunday.

Hurricane categories explained

Meteorologists use the Saffir-Simpson Hurricane Wind Scale to measure a hurricane’s strength,with Category One being the weakest and Category Five the strongest.Category One: winds of 74 to 95 mph and minor damage,such as falling debris and older mobile homes destroyed.Category Two: winds of 96 to 110 mph with well-constructed framed homes sustaining major roof and siding damage.Category Three: winds of 111 to 129 mph,with water and electricity unavailable for several days to weeks after the storm passes.Category Four: winds of 130 to 156 mph,with well-built framed houses potentially sustaining severe damage.Category Five: winds of 157 mph or higher with a high percentage of framed houses destroyed,total roof failure and wall collapse.Evan Thompson,the principal director of the Meteorological Service of Jamaica,said the storm surge is expected mainly over the southern side of the island.Some foreign governments are also preparing for the hurricane’s arrival in Jamaica.The government of Antigua and Barbuda is housing visiting students at a hotel in Kingston. As of Sunday morning,52 of them had checked in.The local airport has already been closed in preparation (Picture: AP)The storm is gaining strength in the warm Caribbean waters (Picture: Reuters)Students from other islands were staying at the same hotel,though it remained unclear whether they were sponsored by their governments.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.Haitian authorities said three people had died as a consequence of the hurricane,and another five were injured because of a collapsed wall.Many residents are still reluctant to leave their homes,Haitian officials said.The storm damaged nearly 200 homes in the Dominican Republic and knocked out water supply systems,affecting more than half a million customers. It also downed trees and traffic lights,unleashed a couple of small landslides and left more than two dozen communities isolated by floodwaters.Melissa is the 13th named storm of the Atlantic hurricane season,which runs from June 1 to November 30.The US National Oceanic and Atmospheric Administration had predicted an above-normal season with 13 to 18 named storms.