MIAMI -- Tropical Storm Gaston is strengthening as it moves over the far eastern Atlantic.

The storm's maximum sustained winds had increased Tuesday to 100 kph. The U.S. National Hurricane Center says Gaston is expected to become a hurricane by Wednesday.

Gaston is centred about 1,230 kilometres west of the southernmost Cabo Verde Islands and is moving west-northwest at 30 kph.

The storm is expected to turn toward the northwest and decrease in forward speed in the next couple of days.

Elsewhere, Fiona broke apart in the Atlantic and Kay became a remnant low in the Pacific.