"Showers and thunderstorms located over the Florida peninsula, the southeastern U.S. coast, the northwestern Bahamas, and the adjacent Atlantic and Gulf waters are associated with a broad trough of low pressure," the National Hurricane Center said.

As the National Hurricane Center watches system off Florida's coast for potential development, a flood watch has been issued for four counties.

If the storm becomes tropical later this week, it will be the first tropical storm of the Atlantic hurricane season.