Tropical depression Fred is moving along Cuba's northern coast and could regain tropical storm status as it moves towards the Florida Keys and southwest Florida, forecasters say.
Meanwhile, still east of the Caribbean Sea, forecasters were watching a tropical depression that they said would likely become Grace, the seventh named storm of the Atlantic hurricane season.
A tropical storm warning was in effect for several islands including Antigua and Barbuda, Anguilla, Saint Martin and Saint Barthelemy.
A tropical storm watch was in effect for the British Virgin Islands, US Virgin Islands and Puerto Rico.
The Miami-based National Hurricane Center said Fred had maximum sustained winds of 55km/h and was dropping heavy rain over parts of Cuba, where the main threats were rain and flooding.
A tropical storm warning was discontinued Friday night for a portion of the Florida Keys, including Florida Bay. The warning remained for the Florida Keys west of the Seven Mile Bridge to the Dry Tortugas.
Forecasters said little change in strength was expected in coming hours, though Fred could regain tropical storm status again on Saturday.
The hurricane centre said 7.5-15cm of rain were expected across the Florida Keys and southern peninsula by Monday, with isolated maximums of 20cm.
Once a tropical storm, Fred weakened back to a depression by its spin over Haiti and the Dominican Republic, where it knocked out power to some 400,000 customers and caused flooding that forced officials to shut down part of the country's aqueduct system, interrupting water service for hundreds of thousands of people.
Local officials reported hundreds of people were evacuated and some buildings were damaged.
Fred's centre was about 245km south-southeast of Key West, Florida, and about 75km southeast of Varadero, Cuba. It was headed west at 20km/h.
Fred became the sixth named storm of the Atlantic hurricane season late on Tuesday as it moved past the US Virgin Islands and Puerto Rico.
Australian Associated Press
