Hurricane Irene looks set to be the first hurricane to hit the United States since Ike ripped along the Texas coast in 2008.
In the Caribbean Sea, authorities on the island of Puerto Rico said hundreds of people took to emergency shelters for safety while Irene passed.
It strengthened into a Category 2 hurricane (on a five-step scale) as it swept north of the Dominican Republic.
The storm season in this part of the Atlantic has been busy, with Irene the ninth to be named, in a very costly year in terms of natural disasters.
Authorities along the US Atlantic seaboard have been tracking Irene’s possible path closely. Some models show she might reach as far north as New York City over the next few days.
Haiti is afraid that rain from Irene could bring deadly floods and mudslides. The country is still struggling to recover from last year’s earthquake, and the people are poorly equipped for more than hundred kilometre-per-hour winds.