Tropical Storm Helene was rapidly strengthening in the Caribbean Sea and expected to become a hurricane Wednesday while moving north along Mexico's coast toward the U.S., prompting residents to evacuate,

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

A state of emergency has been declared in Florida where evacuations are underway along the Gulf Coast as Tropical Storm Helene is expected to become a major hurricane before it makes landfall. Residents in the storm's potential path have been told to prepare for up to a week without electricity.