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

Hurricane Erin, churning north in the Atlantic hundreds of miles offshore, is expected to trigger a dangerous storm surge and tropical storm conditions on Wednesday along North Carolina’s Outer Banks...