MIAMI (AP) — Tropical Storm Gaston is getting stronger as it moves over the far eastern Atlantic.

The storm’s maximum sustained winds had increased early Tuesday to near 50 mph (85 kph). The U.S. National Hurricane Center says additional strengthening is forecast and Gaston is expected to become a hurricane by Wednesday.

Gaston is centered about 545 miles (880 kilometers) west of the southernmost Cabo Verde Islands and is moving west-northwest near 20 mph (31 kph).

Elsewhere in the Atlantic, Fiona is barely maintaining its status as a tropical depression. Fiona’s maximum sustained winds are near 35 mph (55 kph). The depression, which is expected to become a remnant low in the next few days, is centered about 455 miles (735 kilometers) south of Bermuda and is moving west-northwest near 13 mph (20 kph).

Meanwhile in the Pacific, Kay has weakened to a tropical depression.