Packing 185-kilometer-per-hour winds and growing stronger, Emily is now a Category Three hurricane on the Saffir-Simpson intensity scale, on which five is the top-force storm.
The storm lashed Grenada and then headed toward Jamaica and Hispaniola island which is shared by the Dominican Republic and Haiti.
Hispaniola’s southern coast was grazed last week by Dennis, leaving at least 40 people dead in Haiti.
Dennis went on to kill 16 in Cuba, one man in Jamaica and five in the southern United States.
Emily was expected to produce heavy rain across much of the southern Caribbean and northern Venezuela, as well as the Netherlands Antilles.
Jamaica was under a hurricane watch, meaning it could be hit by the storm within 36 hours.
In Grenada, where 30,000 people – one-third of the permanent population – remain homeless 10 months after Hurricane Ivan, there were widespread fears about the new storm.
There were no reports of fatalities in Grenada, but authorities said winds peeled off the roofs of homes and damaged others.
In Trinidad’s tiny sister island of Tobago, nearly half the population lost electricity, some homes were damaged and mudslides were reported.
At 2100 GMT, the storm’s center was about 720 kilometers southeast of Santo Domingo in the Dominican Republic, moving west-northwest near 30 kilometers an hour, the US Hurricane center said.
It was moving west-northwest at nearly 33 kilometers an hour, the center said.
The government of the Dominican Republic has issued a tropical storm warning from Punta Salinas westward to the Haitian border. Venezuela also issued a warning for its northern coast.
The government of Haiti has issued a tropical storm warning from the
border with the Dominican Republic to Port-au-Prince.
Dennis, the first hurricane of the season, was estimated to have caused between one billion and five billion dollars in insured losses in the United States, according to Risk Management Solutions.