Puerto Rico declared a state of emergency as Tropical Storm Dorian, which is growing as it moves across the Caribbean, could be upgraded to a Category 1 hurricane when it nears the island still recovering from the devastation of Hurricane Maria.

Dorian, the fourth named storm of the Atlantic hurricane season, has gathered strength since forming as a tropical depression Saturday.

Now, 30 miles southeast of Saint Lucia with 50 mph winds, the tropical storm is traveling northwest at 13 mph, according to the National Hurricane Center.

Dorian is not yet a hurricane but has placed Martinique, Saint Lucia, Saint Vincent and Grenada under a tropical storm warning.