The governors of two mid-Atlantic U.S. states declared emergencies Wednesday as evacuation of the North Carolina coast ahead of approaching Hurricane Earl continues. North Carolina Governor Beverly Perdue issued the declaration during an afternoon briefing at the state emergency operations center in Raleigh. Just to the north, Virginia's Governor Bob McDonnell declared a state of emergency as a precaution, allowing the state to position staff and resources ahead of the storm. Earl's strongest winds are expected to reach the North Carolina coast Thursday night and Friday morning. Perdue warned residents and vacationers along the state's Outer Banks islands to leave those areas immediately. Already, hundreds of cars were backed up in traffic on Highway 12, the only link between the fragile barrier islands and the mainland. Earl spun toward the U.S. east coast Wednesday, driving tourists from North Carolina's vacation islands and threatening to bring damaging winds and waves all along the Atlantic coast through the Labor Day holiday weekend. The hurricane's effect on the east coast will depend on when it makes its expected turn to the northeast. A later-than-expected turn could mean the storm's center makes landfall on the extreme eastern tip of North Carolina as a Category-3 hurricane late Thursday or early Friday. If that happens, hurricane-force winds also could reach Long Island in New York state and Cape Cod in Massachusetts. Even if the storm turns earlier, dangerous currents are likely to be felt to the north of North Carolina.