Fast-moving Hurricane Helene was advancing Thursday across the Gulf of Mexico toward Florida, threatening an “unsurvivable” storm surge in northwestern parts of the state as well as damaging winds, rains and flash floods hundreds of miles inland across much of the southeastern U.

Hurricane Helene is forecast to rapidly strengthen and could hit Florida on Thursday as a Category 4 storm, producing "catastrophic" winds of up to 156 miles per hour (251 km per hour), forecasters said.