MIAMI (AP) — The U.S. National Hurricane Center says a tropical depression moving over the central Atlantic is expected to strengthen to a tropical storm.

The depression’s maximum sustained winds Wednesday are near 35 mph (55 kph). Slow strengthening is expected, and forecasters say the depression is likely to become a tropical storm later in the day.

The depression is centered about 840 miles (1,350 kilometers) west-southwest of the Cabo Verde Islands and is moving west-northwest near 15 mph (24 kph).