The remains of Tropical Storm Ida have inflicted some of the heaviest flooding and erosion that Atlantic Coast beaches have seen in years. NPS units in the impacted area will have quite a cleanup & fix up job on their hands.
Ida will be remembered along the Atlantic Coast as one of those late fall storms that only happens once in a while when atmospheric conditions line up in just the right way (or just the wrong way, if you happen to be on the receiving end). Ida certainly shows that a storm doesn’t need to bear the hurricane label to be a high-energy trouble maker.
If you’ve been following this thing, you know that Ida started out as a low-ranked hurricane (Category 1) in the Gulf before it came ashore in the Florida panhandle as a tropical storm, quickly degraded to an extratropical storm system, turned sharply eastward, and headed for the Atlantic Coast. Now it's of the Carolina coast and is moving out into the Atlantic very slowly, insuring that its effects will be prolonged and intensified.
Higher pressure to the north has forced the storm center to track far to the south, putting a huge chunk of the Atlantic Coast in the sector where airflow is onshore and the pressure gradient is very steep. Since winds flow toward the center of a surface low in a great counterclockwise spiral, coastal areas will get winds from the east or northeast if the storm center lies to the south or southeast. This "nor'easter" weather pattern translates to very heavy rain (up to ten inches in places), gale force winds, surf-torn beaches, overwash that truncates coastal barriers (and their roads), and the generally serious coastal flooding you get when onshore winds don’t allow the normal drainage of water from estuaries and back bays. To put this in even simpler terms, a huge stretch of the Atlantic Coast takes a terrific beating. The Weather Channel folks, who can be whipped into a frenzy at the least provocation, are justified in calling this episode the “Atlantic Assault.”
If you get out your map and look at the affected area, you’ll see that it contains a goodly number of NPS units, including storm-vulnerable national seashores. North Carolina’s Outer Banks, the home of Cape Hatteras and Cape Lookout National Seashores, was hard hit yesterday, and is still getting surf so big and bad that North Carolina landfills will soon be receiving the remains of condemned houses foolishly ensconced on Nags Head beaches.
As Ida moves further out into the Atlantic and further poleward, drawing energy and moisture from the sea in general and the Gulf Stream in particular, the Middle Atlantic Coast moves more and more into play. As this is being written, the Norfolk, Virginia area is bracing for potentially disastrous coastal flooding and the folks at Assateague Island National Seashore are getting ready to take a direct hit. When this storm finally clears the area, the beachfront damage is likely to include severe overwash (cutting coastal barriers into smaller pieces) and a whole syndrome of flooding-erosion-wind damage problems, including storm-erased beaches, roads truncated or buried by sand, downed trees, power outages, and damaged or destroyed beachfront structures.
Tomorrow (Friday), the stretch of New Jersey coast between Cape May and Sandy Hook can expect a nor’easter inflicting more damage than some coastal communities have seen in at least 15 years. The beachfront NPS units in and very near this area most notably include Fire island National Seashore and Gateway National Recreation Area. If you were planning to visit beaches in that area tomorrow, you’d be well advised to find something else to do.
Southern New England comes into play last. This will make for very interesting times at Cape Cod National Seashore.
If you want to see the Doppler Radar National Mosaic, which is pretty impressive, visit this NOAA site. For the best view, click on "Full Resolution Version" at the bottom left of the radar image that pops up on screen. Then click on any part of that map for a more detailed view.
Not long after the last traces of Ida finally disappear into the Atlantic, damage assessment teams will reckon the cost of repairs and the extent of ecological disruption at the NPS units subjected to the Atlantic Assault. Expect some big numbers.