UPDATE | National Seashores Bracing For Hurricane Erin's Impacts

Editor's note: This updates with closures at Assateague Island National Seashore and Tropical Storm Warning issued for Cape Hatteras and Cape Lookout national seashores.

Though hundreds of miles off the Outer Banks of North Carolina, Hurricane Erin was whipping into a furious tempest threatening to inundate Cape Hatteras and Cape Lookout national seashores this week with towering waves and floodwaters.

Risks to human life posed by the storm that wasn't expected to get closer than 150 miles to land prompted Assateague Island National Seashore in Virginia and Maryland on Tuesday to close the oversand vehicle areas in both states, close all oceanside beaches due to dangerous rip currents, and close at least some of the parking lots at the Chincoteague Beach.

The greatest risks, as of Wednesday morning, posed by the lumbering storm were for Cape Hatteras and Cape Lookout on the Outer Banks of North Carolina, which were under both a tropical storm warning and a storm surge warning.

Predictions of breakers 20 feet tall and storm surges that could rearrange the barrier islands the two seashores stand upon were in the rearview mirrors of thousands fleeing Cape Hatteras on Monday in response to a mandatory evacuation order issued by two North Carolina counties, Dare and Hyde. Highway 12, a thin ribbon of asphalt that runs the length of Cape Hatteras, is expected to once again face the ocean's wrath.

"I wouldn't be surprised to see a few more houses go (into the ocean) in Rodanthe and maybe even in Buxton," said Robert Young, director of Western Carolina University's Program for the Study of Developed Shorelines, referring to vacation homes that years of coastal erosion have placed in precarious position on the surf line.

"The problem with Hatteras is that we can't allow it to breathe and move in the same way that we can allow Cape Lookout to move because we have Highway 12 and we have infrastructure," Young continued during a phone call Monday. "In some stretches of Cape Hatteras National Seashore there are investment homes literally right behind the strip that the park owns, which is the beach, essentially. And we have for decades now been trying to push up sand dikes in front of Highway 12. This is a part of the never-ending saga of trying to maintain a transportation corridor on one of the country's most exposed barrier islands."

While the exact track of Erin is uncertain for later this week, the National Hurricane Center has predicted flooding across the Outer Banks beginning late Wednesday. A storm surge of up to four feet was predicted from the northern tip of Cape Lookout National Seashore north to Duck on the northern end of Cape Hatteras National Seashore.

“People should follow evacuation orders. Hurricane Erin is expected to blast parts of the Outer Banks with 60-to-80-mph wind gusts, several feet of storm surge and waves reaching 15-20 feet. Coastal flooding and surge could wash away dunes and leave roads submerged,” AccuWeather Lead Hurricane Expert Alex DaSilva warned. “These dangerous conditions could leave roads impassable for days, making rescues and evacuations nearly impossible. Some beach houses in areas battling beach erosion could be damaged or even collapse into the rough surf this week.”

“Erin is a remarkably powerful storm," added DaSilva. "It exploded into a Category 5 hurricane with winds reaching 160 mph over the weekend. Erin has since lost wind intensity, but the size of the storm has grown dramatically. Tropical-storm-force winds will likely extend outward more than 230 miles from the center of the storm.”

Six years ago, in September of 2019, what initially appeared to be a small hurricane turned into a relative monster for the Outer Banks. Hurricane Dorian was labeled a Category 1 hurricane, but its path took it perilously close to the Outer Banks, generating a wall of water maybe 9 feet high that swept across the northern end of Cape Lookout, swamping historic Portsmouth Village and, overall, slicing up the seashore's barrier islands into islets.

The hurricane carved more than 50 breaches in Cape Lookout's three barrier islands, and while most naturally filled back in, a few remain today, said B.G. Horvat, the seashore's chief of interpretation, on Monday. While Erin is farther out to sea than Dorian was, the ranger said "it looks like a lot of the impacts will be up more near Cape Hatteras, but our northern end of the park, Portsmouth Island" could be hammered by the storm.

Cape Lookout stands out in comparison to Cape Hatteras and Cape Cod, as those two national seashores reside on barrier islands that have been heavily built out, while Lookout's barrier islands are dunes and maritime forests and a lighthouse with its adjacent keeper's house. There is no paved road running through the islands, no modern-day villages to lure tourists.

"Barrier islands are storm-adapted places," said Young. "They need storms, or at least the ecosystems that they support need storms. Take piping plovers, for example. They need un-vegetated sand flats. Storm wash-over is the best. To some degree I celebrate places like Cape Lookout because those are barrier islands that are still allowed to respond naturally to storms, to move around. Our touch there is still pretty light and so whatever happens on Cape Lookout is largely going to be what nature intends."