Tropical Storm Helene formed Tuesday in the Caribbean Sea and could strengthen into a major hurricane while moving north toward the U.S., forecasters said.

Forecasters say they expect Tropical Storm Helene in the Caribbean Sea to strengthen rapidly and become a hurricane as it moves north across the Gulf of Mexico toward the United States

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,