HAVANA >> Tropical Depression Fred headed for a drenching of Cuba and the Bahamas on Thursday on a forecast track that would carry it toward South Florida as a tropical storm by Saturday.

The main threat to the U.S. appeared to be heavy rains affecting Florida and parts of the Southeast starting on Friday, according to the U.S. National Hurricane Center.

Forecasters issued a tropical storm watch Thursday evening for the Florida Keys and the state’s southwest coast.

It said 3 to 6 inches of rain were expected across the Florida Keys and southern peninsula by Monday, with isolated maximums of 8 inches.

The tropical storm watch is in effect for the Florida Keys from Ocean Reef to the Dry Tortugas, and for the southwest coast of the Florida Peninsula from Bonita Beach to Ocean Reef, forecasters said.

Already a tropical storm, Fred was weakened back to depression force 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. There were no immediate reports of casualties.

Heavy rains continued to pound Hispaniola, which the two nations share, on Thursday.

The Hurricane Center said the storm had maximum sustained winds of 35 mph Thursday evening while centered north of Cuba’s eastern tip.

It was about 470 miles east-southeast of Key West, Florida, and 165 miles east of Camaguey, Cuba.

It was heading west-northwest at 12 mph.

Fred was expected to produce 3 to 5 inches of rain across the Dominican Republic and the western Bahamas, as well as 1 to 3 inches over Haiti, the Turks and Caicos, the eastern Bahamas, and Cuba.

Fred became the sixth named storm of the Atlantic hurricane season late Tuesday as it moved past the U.S. Virgin Islands and Puerto Rico.