(METEOROLOGYNEWS.com) The barrier island coast from Cape Lookout to Cape Hatteras was impacted directly by the Hurricane Irene’s strongest winds when the Category 1 Hurricane made landfall on August 27, 2011.
Satellite Imagery of Hurricane Irene at its highest intensity: Category 3 several days before making landfall on the Outer Banks of North Carolina.
Models indicate the maximum storm surge along the ocean-facing side of the barrier islands from Cape Lookout to Cape Hatteras was roughly 2 m (or approximately 6 feet). Additionally, 7-meter wave heights observed on the open coast contributed to both erosion of some areas of coastline as well as build-up (deposition of sand) in other areas.
Aerial photographs showing several areas of the Outer Banks both before and after Hurricane Irene demonstrate the destructive force of the storm surge and catastrophic wave motions that resulted from the storm.
Location 1: Vertical aerial photographs of Core Banks, NC, from June 12, 2010 and August 28, 2011; one day after landfall of Hurricane Irene. The red line in the lower photo is the location of the oceanfront shore on June 12, 2010. This location is 30-35 km northeast of landfall and in the hurricane's right-front quadrant. A breach has been cut through the barrier island. This is not an unusual occurrence at this location; inlets have been observed here in other photography. Such inlets close naturally by infilling with sand over weeks and months, then reopen during storms like Irene.
Location 2: Oblique aerial photographs of Ocracoke Island, NC, from May 6, 2008 (top, pre-storm) and August 30, 2011 (bottom, post-storm, acquired three days after landfall of Hurricane Irene). The yellow arrow in each image points to the same feature. Overwash deposits of sand extend over the road after the storm. Heavy equipment is at work clearing the road, which appears buried rather than destroyed. Overwash extended tens of meters landward of the road into the marsh grasses on the sound-side of the island.
Location 3: Oblique aerial photographs of Hatteras Village, NC, from May 6, 2008 (top, pre-storm) and August 30, 2011(bottom, post-storm, acquired three days after landfall of Hurricane Irene). The yellow arrow in each image points to the same cottage. Note that the dunes seaward of the cottages may have steepened by wave impacts (the collision regime), but it is not clear with this data. Our lidar results will confirm whether dune erosion occurred. Cottages here appear not to have been significantly impacted by waves and surge.
Location 4: Oblique aerial photographs of Rodanthe, NC, from May 6, 2008 (top, pre-storm) and August 30, 2011 (bottom, post-storm, acquired three days after landfall of Hurricane Irene). The yellow arrow in each image points to the same cottage. A breach was carved through the barrier island, severing NC Highway 12. The storm surge was approximately 2 m high on the sound-side and was less on the ocean-side. Flow from the sound to the ocean may have played a role in cutting the breaches between Oregon Inlet and Cape Hatteras.
Location 5: (Upper image) Oblique aerial photograph of Pea Island National Wildlife Refuge, NC, looking north along the coast on August 30, 2011, three days after landfall of Hurricane Irene. Oblique aerial photos of the central part of upper image from May 6, 2008 (middle, pre-storm) and August 30, 2011 (lower, post-storm). The yellow arrow in each image of the lower images points to the same structure. At this location, two breaches were carved through the island, severing NC Highway 12. With the storm surge higher on the island's sound-side, currents flowing from sound to ocean may have contributed to creating these breaches.