Hurricane Matthew is less than 24 hours from delivering a potentially catastrophic strike on Haiti, and will also strike parts of Jamaica, eastern Cuba and the Bahamas before flirting with parts of the U.S. East Coast into this weekend.
Parts of Jamaica have already been lashed by rain and strong winds, with flood waters blocking roads in the capital, Kingston.
A hurricane warning is in place for Haiti, which is expected to be more seriously affected.
The category-four hurricane is due to bring up to 64 cm (25 inches) of rain.
That in turn could trigger life-threatening landslides and floods.
The Haitian authorities have urged people to stock up on food and water and secure their homes. Thousands are still living in tents following the huge earthquake in 2010.
As it moved slowly over the Caribbean on Sunday evening, Hurricane Matthew brought winds of up to 240km/h (150mph).
Its centre is expected to pass to the east of Jamaica and make landfall to the south-western tip of Haiti late on Monday before reaching Cuba on Tuesday, forecasters say.
Southern areas of Haiti including Jeremie and Les Cayes are expected to see the worst of the heavy rain and treacherous winds.
“Wherever that centre passes close to would see the worst winds and that’s what’s projected to happen for the western tip of Haiti,” US hurricane specialist John Cangilosi said.
“There is a big concern for rains there and also a big concern for [a] storm surge.”
Forecasters say the storm is expected to pass east of Florida through the Bahamas, although it is too soon to say whether it will hit the US coast.
Heavy rainfall in Kingston is expected to be followed by intensely strong winds. Photo: AP
Haitian officials say that about 1,300 emergency shelters have been constructed across the country, sufficient to accommodate 340,000 people. Both airports in Haiti are closed.
Warnings have been broadcast over the radio urging people to pay attention to evacuation warnings, especially because some people are expected to try to stay in their homes to protect them from damage.
Interim President Jocelerme Privert on Sunday advised Haitians to be prepared to move quickly in an address on state radio.
“To those people living in houses that could collapse, it’s necessary that you leave these houses to take refuge in schools and churches,” he said.
In Jamaica emergency services rushed to protect buildings and get people in safe buildings. Long queues formed outside stores and at petrol stations as people stocked up.
The Jamaican government urged people to evacuate and prepare for the storm two days ago.
“No turning back now. It is a matter of how long we have to wait this out,” Minister of Local Government Desmond Mackenzie said.
Matthew is expected to hit Cuba on Tuesday, potentially reaching the colonial city of Santiago de Cuba and the US Navy base of Guantanamo Bay.