Tropical Storm Helene formed over the northwestern Caribbean on Tuesday and triggered a tropical storm warning for the Lower Florida Keys. The storm is forecast to be a major hurricane for the Florida panhandle Thursday.

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 on Wednesday toward the U.S.

Tropical Storm Helene has formed in the northwestern Caribbean Sea and is expected to rock the Florida Gulf Coast later this week as a Category 3 hurricane.  Current sustained winds are 50 miles per hour as it tracks northwest at 12 miles per hour.