Hurricane Melissa began lashing Jamaica with violent gusts on Monday as the US National Hurricane Center upgraded it to a Category 5 storm packing sustained winds of 264 km/h, the largest on record to slam into the Caribbean island.
Cuba, the eastern Bahamas and Turks and Caicos also lie in the expected path of the storm, which will make its way north and east towards Bermuda later this week.
The hurricane is expected to stay well offshore of the United States, bringing only rough surf and minor coastal flooding to the US East Coast.
On Monday at midday local time, Melissa was still 230 km southwest of Kingston, Jamaica, and about 530 km southwest of Guantánamo, Cuba, according to the NHC in Miami.
The hurricane was creeping west at just 5 km/h, the centre said, but would likely make a north-northeastward turn through Jamaica late on Monday and into Tuesday.
The storm's slow movement over unusually tepid Caribbean water had contributed to its ballooning size and strength, the centre's forecasters said, threatening Jamaica with days of never-before-seen catastrophic winds and as much as one metre of rain.
"This will result in extensive infrastructural damage, long-lasting power and communication outages, and isolated communities," the NHC said.
Damian Anderson, a teacher from Hagley Gap, a town nestled in Jamaica's soaring Blue Mountains, said impassable roads had already cut off his community.
"We can't move," Anderson, 47, said. "We're scared. We've never seen a multi-day event like this before."
Nearby Haiti and the Dominican Republic have already faced days of torrential downpours leading to at least four deaths, authorities in those island nations said.
Jamaica has seen many large hurricanes in the past, including Category 4 Hurricane Gilbert in 1988, but a direct hit from a Category 5 would be unprecedented, said Evan Thompson, of Jamaica's Meteorological Service.
Category 5 is the highest on the Saffir-Simpson scale with sustained winds exceeding 250 km/h.
Cuba preparations
Much of the eastern half of Cuba also battened down ahead of the storm's expected landfall late on Tuesday.
Cuban authorities said they had evacuated upwards of 500,000 people living in coastal and mountainous areas vulnerable to heavy winds and flooding.
More than 250,000 people were brought to shelters around Santiago de Cuba, the island's second-largest city, which lies square in the crosshairs of the hurricane's predicted path.
On Monday, authorities cancelled schools, buses and trains until further notice across eastern Cuba ahead of the storm's arrival.
The hurricane was not expected to directly impact the capital Havana.
