A hurricane watch and warnings of storm surges up to 15 feet high were issued Tuesday for almost all of Florida's western coastline as Tropical Storm Helene formed over the Caribbean Sea and headed toward the Gulf Coast.

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.

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, schools to close and officials to declare emergencies in Florida and Georgia.