A fast-strengthening hurricane is closing in on Jamaica and meteorologists say it could be the most intense storm to make landfall on the island in recorded history. Hurricane Melissa is classified as a Category 5 system, with maximum sustained winds of 295km/h (185mph) and a central pressure reported as low as 892 millibars.
The storm has already been linked to fatalities elsewhere in the Caribbean, and Jamaican authorities have issued mandatory evacuations for particularly exposed communities as preparations continue.
Melissa began as a cluster of thunderstorms off West Africa in mid-October and became Tropical Storm Melissa late last week. As it tracked west across the tropical Atlantic and into the Caribbean Sea it underwent rapid intensification, reaching Category 5 strength in under 24 hours.
Warm sea surface temperatures in the Caribbean -- unusually high this season -- provided the energy the storm needed to strengthen quickly. That warm layer of water helps fuel rising moist air and the rotating convection that forms a hurricane, with a calm eye surrounded by an intense eye-wall of wind and rain.
Brian McNoldy, senior research associate at the University of Miami, said: "The ocean is warmer and the atmosphere is warmer and moister because of [climate change]."
He added: "So it tips the scale in favour of things like rapid intensification [where wind speeds increase very quickly], higher peak intensity, and increased rainfall."
In terms of central pressure and wind speed, Melissa ranks among the strongest Atlantic hurricanes of recent decades. Its measured pressure is lower than the 902 millibars recorded for Hurricane Katrina in 2005, a storm that caused enormous loss of life and economic damage.
Hurricane Katrina resulted in 1,392 deaths and damage estimated at $125bn (£94bn). Forecasters have warned that if Melissa approaches Jamaica at near-maximum strength the consequences could exceed those of previous storms that hit the island, such as Gilbert (1988), Dean (2007) and Beryl (2024).
Dr Fred Thomas, a research software engineer at Oxford University's Environmental Change Institute, told the BBC: "This is going to be the strongest hurricane that's ever hit [Jamaica], at least in the records we have."
Although peak winds are extreme, Melissa's forward speed has been unusually slow -- moving west at roughly 5km/h at times -- which increases the time any one location will be exposed to heavy rain, storm surge and destructive winds.
Dr Thomas said: "Imagine a metre of rainfall coming down in a whole basin and then being channelled down into a river network. That's going to be metres and metres of flooding by the time it reaches the lower parts of that drainage network. So the flooding will probably result in a large loss of life, I imagine."
Research indicates some hurricanes are moving more slowly than in the past, which can amplify flooding impacts. Scientists are exploring whether changes in large-scale atmospheric circulation related to climate change play a role, though natural variability also contributes.
Jamaica's prime minister has warned of the severity of the hazard. Andrew Holness said: "no infrastructure can withstand a Category 5".
Building codes in urban areas often require reinforced concrete construction, which can offer better wind resistance. However, many rural and hillside communities have more fragile, timber-based housing and are therefore at heightened risk from wind, flooding and landslides.
Dr Thomas observed: "Anything built to that code should be pretty strong in terms of the wind, but the wind has only one impact."
He added: "The frightening thing about Melissa is not just the wind - it's the rain and the storm surge. You could have your whole ground floor completely inundated and then part of the first floor as well."
Power and water systems, transport links and communications are all at risk. Falling trees and debris are likely to damage power lines and floodwaters can overwhelm sewage and freshwater supplies. Mountain roads may be cut by landslides, isolating communities and delaying relief.
Dr Patricia Green, an architect and preservationist based in Kingston, told the BBC: Jamaica is "unprepared to cope effectively" with major storms. She recalled how "a couple of hours of rainfall" in September caused "massive flooding" in the capital, exposing weaknesses in urban planning and drainage.
Modern sealed-glass construction can also increase vulnerability by preventing air flow and raising internal pressures during extreme winds, making walls and roofs more susceptible to failure.
Poorer neighbourhoods, especially those along riverbanks and in gullies, are particularly exposed -- a legacy in some cases of historical land allocation that left disadvantaged communities on marginal ground.
Dr Thomas warned: "Power goes out, and then telecommunications go. Hospitals have backup for a while, but often not long enough. And the airport's closed, which means aid can't get in quickly."
The storm has already been blamed for several deaths in Haiti and the Dominican Republic. Jamaica's minister of health reported three people died on the island while preparing for Melissa.
Some communities, including low-lying coastal settlements and small peninsulas such as Port Royal, are on mandatory evacuation lists. Dr Thomas said of Port Royal: "It's sort of a long spit of land and it's extremely exposed with a seven or eight-mile drive back to the mainland, so it could be quite easily cut off."
Hannah Cloke, professor of hydrology at the University of Reading, said: "This is one of those worst-case scenarios that you prepare for but desperately hope never happen." She added: "The whole country will have a deep and permanent scar from this beast of a storm. It will be a long and exhausting recovery for those affected."
Authorities are urging people in the storm's projected path to follow evacuation orders, secure property as best they can and prepare for prolonged outages and difficult rescue and relief operations. With airports and roads likely to be disrupted, the initial phase of recovery and delivery of aid could be delayed even after the eye passes.
Emergency services, humanitarian agencies and communities across Jamaica are preparing for an intense period of impact and a potentially extended recovery ahead.