Hurricane Fiona is continuing to strengthen - threatening lives in parts of the Caribbean, say US forecasters.
The National Hurricane Center (NHC) said the category two storm currently packing speeds of 115mph (185km/h) could even worsen to a category four - the second-highest designation.
Rain is lashing Puerto Rico, where at least two people have died and 90% of the island remains without power.
Dominican Republic President Luis Abinader says damage is "considerable".
The hurricane was about 10 miles (15km) north-west of Grand Turk Island in the Turks and Caicos Islands at 12:00 GMT on Tuesday, the NHC said.
Mr Abinader has declared three eastern provinces of Dominican Republic to be disaster zones, amid warnings from the NHC of "heavy rainfall and life-threatening flash flooding".
Several villages were cut off in the country as floodwaters rose, while hundreds of people were forced to leave their homes and thousands were left without power.
Lexie Wilcox, who lives in the easternmost province of Altagracia, said it was the worst hurricane she had experienced and had hit her local area much harder than Hurricane Maria in 2017, which killed nearly 3,000 people in Puerto Rico.
On Monday morning there were trees down, with roads blocked and a lot of flooding.
She was unable to sleep, spending the night mopping up rainwater.
The roof has been partially blown off her shed, and a security sign blew off her house.
Ms Wilcox and her neighbours are without electricity, and believe this may take days to be fixed as the storm is still ongoing.
Connection returned for a few minutes on Monday, just long enough to allow Ms Wilcox, who is Canadian, to watch the end of Queen Elizabeth II's funeral while the hurricane raged outside.
The NHC warned earlier of ongoing threats to life in Puerto Rico because of "catastrophic flooding". An estimated 1.3 million homes and businesses in Puerto Rico are currently without power, Reuters news agency reports. Fiona made landfall there on Sunday, causing not only deluges but also widespread landslides and mudslides.
US President Joe Biden pledged to scale up support for the island following a conversation with the governor.
Images shared on social media have shown cars submerged and people attempting to wade down streets filled with water, while efforts continue to rescue those who have got stranded.
The victims in Puerto Rico were a 58-year-old man who died after being swept away by a river, while another in his 30s died in a generator fire.
The storm caused an island-wide blackout which providers warned could take days to fix.
Puerto Rico's electricity grid remains fragile after the island was devastated by Hurricane Maria - the most powerful storm in its history.
Some areas of the island face the prospect of 30in (76cm) of rainfall as the storm passes.
Storm conditions have also been forecast in the Bahamas, while people in Bermuda have been advised to monitor Fiona's progress.