Helene is strengthening as it moves toward the U.S. Gulf Coast. It is expected to become a hurricane today and will hit Florida's Big Bend on Thursday.

The highest landfall probability is somewhere along the eastern part of the Florida Panhandle late Thursday evening, forecasters said.

Hurricane Helene is forecast to bring dangerous storm surge to the Tampa Bay area. "The residence halls will be closed after the evacuation concludes, and there will be no entry allowed into residential buildings until they are reopened following the storm," the university said in a message to students.