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.

Over the weekend, northern portions of the Leeward Islands, the Virgin Islands, and Puerto Rico are expected to receive tropical rain ranging from 2 to 4 inches, with isolated totals up to 6 inches. Flash flooding, landslides and mudslides will be the main concerns over the next several days.

Hurricane Erin could 'at least double or triple in size' next week and the track has shifted south, but remains likely to turn away from the East Coast.

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 say Hurricane Erin has formed in the Atlantic Ocean on track to bring heavy rains that could lead to flooding and landslides in Puerto Rico and the Virgin Islands.

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.