Helene is expected to rapidly intensify into a major and massive hurricane with 115-mph winds by the time it makes landfall Thursday.

Tropical Storm Helene continues to organize over the northwestern Caribbean Sea, according to the National Hurricane Center.

A state of emergency has been declared in Florida where evacuations are underway as Tropical Storm Helene strengthens. Residents in the storm's potential path have been told to prepare for up to a week without electricity.