By Harriet McLeod
CHARLESTON, S.C. (Reuters) - Hurricane Fred strengthened on Monday in the eastern Atlantic as it approached the Cape Verde islands but was forecast to weaken in the coming days, while the remnants of Tropical Storm Erika brought flooding to parts of South Carolina, according to U.S. forecasters.
The center of Fred is expected to pass near or over the northwestern Cape Verde islands, an archipelago off the west coast of Africa with a population of 525,000.
Fred had maximum sustained winds of 80 miles per hour (130 km per hour), but was expected to gradually dissipate after passing the Cape Verde islands late on Monday, then move away on Tuesday, the National Hurricane Center (NHC) said.
Fred was not expected to threaten the Caribbean or the United States.
"Weakening is forecast during the next couple of days," government forecasters said.
The NHC said it was rare for a storm to form so close to the coast of Africa. Fred was the first hurricane to go through the Cape Verde islands since 1892, according to the official Atlantic tropical cyclone record which begins in 1851.
Tropical Storm Erika dissipated over Cuba on Saturday after killing at least 20 people in the small eastern Caribbean island of Dominica, and one person in Haiti.
Its remnants brought thunderstorms to Florida over the weekend before moving into South Carolina on Monday.
By 9:30 a.m. EDT, almost 6.5 inches (16.5 cm) of rain had fallen at South Carolina's Charleston International Airport, according to the National Weather Service.
In Charleston's outlying suburbs, some residents reported on social media that they could not get out of their driveways, and local TV stations showed pictures of cars submerged above their windows and over the hoods.
Charleston police closed streets in peninsular Charleston, which is at or slightly above sea level.
The torrential rain coincided with "king tides," especially high tides caused by a full moon and expected to last until Wednesday, city officials said.
(Additional reporting by David Adams in Miami; Letitia Stein in Tampa, Florida; and Kevin Jose in Bengaluru; Editing by Jeffrey Benkoe and Lisa Shumaker)