Forecasters say Tropical Storm Erin, which formed in the eastern Atlantic Ocean on Monday, is on the verge of becoming the Atlantic season's first hurricane.

Hurricane Erin was a Category 4 storm again Monday morning and is expected to grow even larger and stronger, according to the latest advisory from the National Hurricane Center.

From Cape Lookout to Duck, North Carolina, 2 to 4 feet of storm surge flooding is possible along the coast, according to the hurricane center.

Hurricane Erin's higher tides and big waves are battering much of the East Coast, with the large storm prompting the expansion of tropical storm and coastal flooding advisories Wednesday. Beachfront property owners are bracing for the worst amid predictions of a storm surge of up to 4 feet and significant coastal erosion.

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.

A state of emergency and a mandatory evacuation order is in place for Ocracoke Island, in North Carolina's Outer Banks.