Hurricane Melissa is forecast to become a rare category five storm as it turns towards Jamaica, bringing life-threatening flash flooding and landslides.
The cyclone, which had winds of up to 120 mph (195 km/h) as of 06:00 GMT, is currently turning north-west in the Caribbean and is expected to make landfall by Tuesday, according to the US National Hurricane Center (NHC).
It warns of power cuts and damage to infrastructure as Melissa brings up to 30 inches (76cm) of rain and sea level surges as high as 13ft (4m) above ground. "Seek shelter now," residents have been told.
Melissa is the 13th hurricane in this year's Atlantic season, which typically ends in November.
A category five hurricane is the strongest type, with winds of at least 157mph.
