Here are a few highlights of what might be happening to all us of on the East Coast over the next 96 hours.
We’ve all been watching the computer models, which have been steadily moving their forecast tracks for Irene more to the east–first into Florida, then Georgia, then South Carolina, then North Carolina, then offshore of North Carolina–and it seemed that this storm would do what so many many storms have done in the past, brush the Outer Banks of North Carolina, then head out to sea. Irene will not do that. Irene will likely hit Eastern North Carolina, but the storm is going northwards after that, and may deliver an extremely destructive blow to the mid-Atlantic and New England states. I am most concerned about the storm surge danger to North Carolina, Virginia, Maryland, Delaware, New Jersey, New York, and the rest of the New England coast. Irene is capable of inundating portions of the coast under 10 – 15 feet of water, to the highest storm surge depths ever recorded. I strongly recommend that all residents of the mid-Atlantic and New England coast familiarize themselves with their storm surge risk.
The models have edged their tracks westwards in the last cycle of runs, and there are no longer any models suggesting that Irene will miss hitting the U.S. The threat to eastern North Carolina has increased, with several of our top models now suggesting a landfall slightly west of the Outer Banks is likely, near Morehead City. After making landfall on the North Carolina coast Saturday afternoon or evening, Irene is likely to continue almost due north, bringing hurricane conditions to the entire mid-Atlantic coast, from North Carolina to Long Island, New York. This makes for a difficult forecast, since a slight change in Irene’s track will make a huge difference in where hurricane conditions will be felt. If Irene stays inland over eastern North Carolina, like the ECMWF and GFDL models are predicting, this will knock down the storm’s strength enough so that it may no longer be a hurricane once it reaches New Jersey. On the other hand, if Irene grazes the Outer Banks and continues northwards into New Jersey, like the GFS model is predicting, this could easily be a Category 2 hurricane for New Jersey and Category 1 hurricane for New York City. A more easterly track into Long Island would likely mean a Category 2 landfall there.
Irene’s large size, slow motion, arrival at high tide, and Category 3 strength at landfall in North Carolina will likely drive a storm surge of 8 – 10 feet into the heads of bays in Pamlico Sound, and 3 – 6 feet in Albemarle Sound. As the storm progresses northwards, potential storm surge heights grow due to the shape of the coast and depth of the ocean, though the storm will be weakening. If Irene is a Category 1 storm as it crosses into Virginia, it can send a storm surge of 4 – 8 feet into Chesapeake Bay and Norfolk. I give a 50% chance that the surge from Irene in those locations will exceed the record surges observed in 2003 during Hurricane Isabel. The region I am most concerned about, though, is the stretch of coast running from southern Maryland to Central New Jersey, including Delaware and the cities of Ocean City and Atlantic City. A Category 1 hurricane can bring a storm surge of 5 – 9 feet here. Irene’s large size, slow movement, and arrival at the highest tide of the month could easily bring a surge one Category higher than the storm’s winds might suggest, resulting in a Category 2 type inundation along the coast, near 10 – 15 feet. This portion of the coast has no hurricane experience, and loss of life could be heavy if evacuation orders are not heeded. I give a 30% chance that the storm surge from Irene will bring water depths in excess of 10 feet to the coasts of Maryland, Delaware, and New Jersey.
NOAA’s SLOSH model predicts that a mid-strength Category 2 hurricane with 100-mph winds could drive a 15 – 20 foot storm surge to Manhattan, Queens, Kings, and up the Hudson River. JFK airport could be swamped, southern Manhattan would flood north to Canal Street, and a surge traveling westwards down Long Island Sound might breach the sea walls that protect La Guardia Airport. Many of the power plants that supply the city with electricity might be knocked out, or their docks to supply them with fuel destroyed. The more likely case of a Category 1 hurricane hitting at high tide would still be plenty dangerous, with waters reaching 8 – 12 feet above ground level in Lower Manhattan. Given the spread in the models, I predict a 20% chance that New York City will experience a storm surge in excess of 8 feet that will over-top the flood walls in Manhattan and flood the subway system. This would most likely occur near 8 pm Sunday night, when high tide will occur and Irene should be near its point of closest approach. Such a storm surge could occur even if Irene weakens to a tropical storm on its closest approach to New York City.
So, basically, either North Carolina takes the full brunt of this storm or we’re looking at an unimaginable amount of destruction just from the storm surge alone. Of course, the wind damage will be extensive and flash flooding will be widespread. I know this is exactly what our economy needs.