Forecasters say Tropical Storm Henri formed in the Atlantic Ocean but it could be short-lived.

The U.S. National Hurricane Center said Tuesday afternoon the storm was about 600 miles east of the northern Leeward Islands.

The storm is moving west-northwest about 18 miles per hour and is expected to stay well to the north of the Lesser Antilles.

Its maximum sustained winds are near 40 mph.

Forecasters say the eighth named storm of the Atlantic season could weaken below tropical storm strength as early as Wednesday night.