Millions of people living along the Gulf Coast are being urged to make sure preparations are in place as the next tropical threat to the U.S. brews in the Caribbean, and there are increasing signs that the ingredients needed for a tropical storm or hurricane to form are coming together.

The National Hurricane Center has again increased the development chances for a tropical disturbance in the Caribbean Sea, meaning millions of people from Florida to Louisiana should prepare for potential impacts Tropical Storm or Hurricane Helene later this week.