The disturbance is forecast to become a hurricane Wednesday and will strengthen as it crosses the eastern Gulf of Mexico.

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.

A shallow coastal shelf makes cities along the Gulf of Mexico more vulnerable to storm surges during hurricanes.