Two more tropical systems trail Hurricane Erin, which is following a projected course that brushes past the East Coast without making landfall.

Forecasts nudge Erin's likely path to the west, increasing the risks at U.S. beaches. Experts say the storm's massive size, rather than windspeed, is what makes it a threat.

By Tuesday morning, Erin had lost some strength from previous days and dropped to a Category 2 hurricane with maximum sustained winds of 110 mph (175 kph), the National Hurricane Center in Miami said.

Hurricane Erin was a Category 4 storm Monday morning and is expected to retain major hurricane status through the middle of the week.

Hurricane Erin is moving east of the U.S. coast and will bring strong waves and rip currents to Florida's east coast – and it comes as the National Hurricane Center is eyeing two more tropical waves in the Atlantic.

Hurricane Erin weakened to a category 3 hurricane during the early hours of Aug. 19 as it moves closer to the East Coast, according to the National Hurricane Center. As of 5 a.m. Aug. 19, Erin was located 675 miles southwest of Bermuda and 750 miles from Cape Hatteras,