NEW YORK (Reuters) - Recently-downgraded Gaston remained a tropical depression on Thursday as it churned west-northwest in the central Atlantic on a path that will likely take it into the Caribbean Sea, the National Hurricane Center said Thursday.
It was still too early to tell if the system would move into the Gulf of Mexico and threaten energy production.
Gaston's winds faded to 35 miles per hour (56 km per hour) Thursday morning, down from 40 mph overnight, the last report from the NHC showed.
The system was expected to restrengthen gradually over the next 36 hours and could still become the 2010 Atlantic storm season's fourth hurricane by Monday.
Gaston was located about 1,000 miles west of the southernmost Cape Verde Islands, moving west-northwest at just 7 mph.
Most computer models show the system tracking in a westerly direction into the Caribbean.
Meanwhile, Hurricane Earl, located in the western Atlantic about 245 miles south of Cape Hatteras, North Carolina, weakened to a Category Three storm, as winds slipped to 125 mph from 145 mph earlier Thursday. Further weakening was expected.
While Earl was not forecast to make a U.S. landfall, it was expected to pass near North Carolina's Outer Banks late Thursday and approach southeastern New England late Friday.
Oil refiners and nuclear power plants along the East Coast were monitoring Earl as it made its way up the seaboard.
Tropical Storm Fiona was also located in the western Atlantic about 520 miles south-southwest of Bermuda with winds unchanged from earlier at about 50 mph.
Fiona was mainly expected to steer north and then northeast, passing near Bermuda by early Saturday.
Slow weakening was forecast during the next 48 hours, and Fiona was not expected to attain hurricane strength.
NHC was also monitoring a tropical wave in the east Atlantic a few hundred miles east-southeast of the Cape Verde Islands.
Some slow development of this system was possible over the next couple of days as it moves westward at about 10 mph, but NHC gave it a low, 10-percent, chance of becoming a tropical cyclone during the next 48 hours.
(Reporting by Joe Silha; Editing by Marguerita Choy)
