MIAMI - The lower and middle Florida Keys are now under a tropical storm warning as Tropical Storm Rafael is forecast to grow steadily as it churns past Jamaica's west coast on a path for Cuba, where it's expected to arrive later in the week as a hurricane.

Florida residents along the Gulf Coast are being urged to monitor Tropical Storm Rafael as it strengthens in the Caribbean and heads towards the U.S. The Florida Division of Emergency Management is advising residents to stay informed and be prepared for potential impacts from the storm.

Tropical Storm Rafael is forecast to become a hurricane in the northwestern Caribbean near the Cayman Islands before making landfall in Cuba.