Hurricane Erin has been downgraded to a Category 3 hurricane but is gaining in size and raising the risk of life-threatening surf later this week along the U.S.

Much of North Carolina’s Outer Banks region is under a tropical storm watch with Hurricane Erin expected to skirt the area Wednesday through Thursday, according to the National Hurricane Center.

A disturbance in the Atlantic following Hurricane Erin is now expected to track northward, according to NHC data.

While Erin won't hit the U.S. directly, the storm's biggest impact on the East Coast will be along the Outer Banks of North Carolina, where coastal flood watches, tropical storm watches and storm surge watches are in effect. The storm surge could be as high as 4 feet.