Hurricane Helene has been intensifying with the help of unprecedentedly warm waters in the Gulf of Mexico and is now barreling toward Florida.

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.

Helene’s storm clouds are expected to become better organized with a more defined rotation as it enters a favorable environment.