Tropical Storm Erin formed in the eastern Atlantic Ocean on Monday, forecasters said. The storm could strengthen to become the Atlantic's first hurricane of the season.

Hurricane forecasters were eyeing two developing tropical systems in the Atlantic Ocean Aug. 10 – one of which could pose an eventual risk to the United States.

Forecasters are tracking a new disturbance in the Atlantic Ocean as Hurricane Erin, a Category 5 storm, undergoes an eyewall replacement cycle, according to a Saturday night update from the National Hurricane Center.

A westward-moving tropical wave could produce an area of low pressure in the tropical Atlantic late in the week of Aug. 18, the hurricane center said on Aug. 16. The center shows a 20% chance of storm formation over the next week.

Jean-Raymond Bidlot, senior scientist in ocean modeling at the European Centre for Medium-Range Weather Forecasts (ECMWF) told Newsweek that Erin is forecast to strengthen over the next week as it heads toward the U.S. East Coast, reaching peak intensity offshore from Cape Hatteras.

Forecasters are watching a tropical disturbance with very high chances of formation as it moves west of Africa in the Atlantic Ocean. The low pressure system, causing strong winds and rough seas, is near the northwest Cabo Verde Islands and has a 90% chance of organizing into a tropical depression over the next two days.

Hurricane Erin is forecast to remain well offshore but still bring hazardous currents and possible erosion like previous offshore hurricanes before it.