The hatched areas on the National Hurricane Center's tropical outlook map indicate "areas where a tropical cyclone — which could be a tropical depression, tropical storm or hurricane — could develop," said National Hurricane Center Deputy Director Jamie Rhome.

Tropical Storm Erin is expected to strengthen into a hurricane later this week in the Atlantic Ocean, according to the National Hurricane Center.

A system in the Gulf of America could bring heavy rainfall and flash flooding to portions of Florida as it moves onshore.