Erin, the first hurricane of the season, is now forecast to become a Category 4 by Sunday. Here's where it could head in the week ahead.

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.

Hurricane Erin will continue to strengthen as it approaches the Leeward Island and Puerto Rico, where it will threaten with tropical downpours, pounding surf and strong winds.