The Atlantic basin includes the northern Atlantic Ocean, Caribbean Sea and Gulf of America, as the Gulf of Mexico is now known in the U.S. per an order from President Trump. NOAA and the National Hurricane Center are now using Gulf of America on its maps and in its advisories.

Erin is the fifth named storm to develop during the Atlantic hurricane season, which started just over two months ago. Last week, Tropical Storm Dexter formed in the western Atlantic but didn't pose a threat to land. In early July, Tropical Storm Chantal made landfall on the Carolina coast, bringing deadly flooding to the region.