Florida is bracing for what could be the United States’ heaviest-hitting hurricane so far this season, as an area of thunderstorms builds strength in the Caribbean Sea before potentially bringing life-threatening storm surge and hurricane-force winds to the Southeast later this week.

Hurricane Helene is expected to form Wednesday and strengthen into a major hurricane before reaching Florida’s Gulf coast from Tampa to Pensacola Thursday.

Most forecast models suggest a hurricane landfall on Thursday, and experts say the storm could be at least a Category 3.