A catastrophic Category 5 hurricane was bearing down on Jamaica on Monday, October 27 afternoon with sustained winds of up to 282kph (175mph), threatening to become the strongest storm the Caribbean island has ever experienced, according to the US National Hurricane Center.

Hurricane Melissa was positioned south of Kingston at 2pm (1800 GMT) and was expected to pass over Jamaica late Monday or early Tuesday before traversing eastern Cuba and moving towards the Bahamas and Turks and Caicos by October 29, the NHC said. Moving at an exceptionally slow pace of just 5kph (3mph), the storm was forecast to subject Jamaica to multiple days of devastating winds and up to 91cm (3 feet) of rainfall.

Prime Minister Andrew Holness warned that regional infrastructure could not withstand such a powerful storm, according to Reuters. He appealed for international assistance whilst warning that the hurricane would cause significant destruction to agricultural land, residential properties and essential infrastructure.

The storm's wind field exceeded the length of Jamaica itself, an island with major airports situated near sea level. Forecasters attributed the hurricane's intensification to its sluggish movement across unusually warm Caribbean waters.

Melissa posed a severe storm surge threat along Jamaica's southern coastline, with water levels potentially reaching 4 metres (13 feet) above normal, whilst some areas could see rainfall totals of up to 76cm (30 inches), AP reported.

Holness implemented mandatory evacuation orders for portions of southern Jamaica, including the historic settlement of Port Royal, affecting roughly 28,000 residents. Authorities indicated that transport was available, though some residents showed reluctance to leave their properties due to concerns about theft.

The government established an emergency response fund of $33mn, with additional insurance and credit arrangements exceeding those deployed after last year's Hurricane Beryl.

"Tens of thousands of families are facing hours of extreme wind gusts above 100mph and days of relentless, torrential rainfall," said AccuWeather Chief Meteorologist Jonathan Porter, as quoted by Reuters, cautioning that damaged infrastructure would complicate relief efforts.

Evan Thompson, principal director at Jamaica's Meteorological Service, confirmed that whilst Jamaica has weathered significant hurricanes previously—including Category 4 Hurricane Gilbert in 1988—the island has never faced a direct strike from a Category 5 system, AP reported. Porter noted that Melissa's significantly slower progression compared to Gilbert meant affected communities might remain isolated for extended periods.

Haiti and the Dominican Republic had already endured multiple days of intense rainfall, resulting in at least four fatalities—three in Haiti and one in the Dominican Republic, where another individual remained unaccounted for—authorities reported.

More than 3,650 people in southern Haiti were relocated to temporary accommodation, whilst officials in the violence-stricken country suspended air travel and prohibited maritime activities.

Western Haiti was projected to receive up to 41cm (16 inches) of precipitation, creating conditions for catastrophic flooding and landslides, the hurricane centre warned.

Dominican emergency officials reported that the storm had damaged over 750 residences, displaced more than 3,760 individuals and left over half a million people without access to clean water, AP reported.

The hurricane destroyed agricultural crops across three Haitian regions, including 15 hectares (37 acres) of maize, during a period when at least 5.7mn people—representing more than half the nation's population—face severe food insecurity.

In Cuba, authorities implemented a "Cyclonic Alarm Phase" for six eastern provinces and ordered approximately 649,487 people to evacuate from coastal zones and mountainous regions at risk from powerful winds and flooding, according to state media.

Over 250,000 individuals were transported to emergency shelters in and around Santiago de Cuba, the nation's second-largest urban centre, which stood directly in the hurricane's forecast track, Reuters reported. Educational institutions and public transport ceased operations throughout eastern Cuba.

President Miguel Díaz-Canel mandated evacuations for all residents in areas downstream from dams or prone to flooding, and stressed the need to communicate with communities that might underestimate the danger.

The storm was anticipated to make landfall in Santiago de Cuba province on October 28 before returning to sea along the coast between Holguín and Guantánamo, with precipitation totals potentially reaching 51cm (20 inches) across parts of Cuba.

Cuban authorities estimated that Hurricane Melissa might damage as many as 38,000 residences, with many featuring vulnerable roofing.

Approximately 1,000 US military personnel departed Guantánamo Bay in advance of the storm's arrival, whilst several US Navy vessels operating in the region repositioned themselves away from the hurricane's direct trajectory, a US defence official told CBS News.

Prime Minister Philip Davis of the Bahamas similarly mandated evacuations for residents in the archipelago's southern and eastern sections.

Climate scientists caution that hurricanes are intensifying more rapidly due to warming ocean temperatures caused by climate change. Hurricane Beryl previously set records as the earliest and fastest-developing Atlantic hurricane to achieve Category 5 status.