BOSTON, Aug. 27, 2011 – According to catastrophe modeling firm AIR Worldwide, the eye of Hurricane Irene made landfall near Cape Lookout, North Carolina at about 7:30 am EDT, Saturday, August 27. As of the National Hurricane Center’s (NHC) 11:00 am advisory, Irene-now a Category 1 storm (down from Category 2 status yesterday)- Irene is moving to the north-northeast at about 15 mph, and this forward motion is expected to continue over the next 24 hours.
“Maximum sustained winds are near 85 mph,” said Dr. Tim Doggett, principal scientist, AIR Worldwide. “Additional weakening is forecast as Irene traverses eastern North Carolina. Once the storm exits North Carolina and begins its way towards Long Island, it will enter an area of increased wind shear-possibly up to 30 knots. This should prevent Irene from reintensifying; however the very large size of this system will likely prevent any very rapid weakening and Irene is expected to maintain hurricane status at least until second landfall on Long Island.”
As noted, Irene is still a very large storm. Hurricane force winds extend outward up to 90 miles from the center and tropical storm force winds extend outward to 260 miles. Hurricane warnings extend northward from North Carolina through RI and Cape Cod. Tropical storm warnings extend all the way to the border between Massachusetts and New Hampshire.
Dr. Doggett explained, “Eastern North Carolina experienced battering winds and heavy rainfall. Instruments measured a sustained wind of near 60 mph and a gust of 84 mph at Cape Hatteras, 60 miles from the center of the storm at 8:00 am. Rainfall accumulations of 6 to 10 inches, with isolated amounts up to 15 inches, are expected.”
Storm surge of up to 9 feet above ground level in North Carolina level is likely to cause severe beach erosion and possibly structural damage to properties on the Outer Banks.
According to AIR, the majority of single-family residential structures along the U.S. east coast are of wood-frame construction. At wind speeds associated with a strong Category 1 hurricane, these structures can experience damage to roof coverings and wall claddings. Failure of roof structures may occur in instances of improper fastening between the roof and building frame.
Despite weakened wind speeds, Irene’s heavy rainfall accumulations could result in widespread damage to homes as a result of downed trees-a possibility exacerbated by the large geographic extent of the storm and, in some areas, by soils already saturated from previous heavy rainfall. Wind damage can devastate the affected area and you can call this service for tree removal Raleigh NC to clear away any debris.
Exposure in low-lying areas is subject to possibly significant damage as a result of storm surge.
The forecast track for Hurricane Irene brings the eye of the storm up and very close to the New Jersey coastline, and inland again on Long Island. The strongest winds will be in the northeast quadrant of the storm system.
Dr. Doggett, continued, “The latest indications suggest that Irene could maintain hurricane strength as far inland as Hartford, where it should arrive by mid-day on Sunday. Although Irene will encounter both cooler ocean temperatures and increased vertical wind shear as it travels northward, the sheer size of the storm is likely to prevent rapid weakening. It should be noted, however, that there is considerable uncertainty in both track and intensity forecasts.”
Irene is currently expected to track well west of Boston, possibly as a weak Category 1 hurricane, but more likely as a tropical storm.
“The last time New England was significantly impacted by a hurricane was in 1991, when Hurricane Bob made landfall near Newport, Rhode Island as a Category 2 storm and tracked just east of Boston,” said Dr. Doggett. “If Hurricane Bob were to recur today, AIR estimates it would produce insured losses of about USD 2.4 billion.”
Of major concern is the storm surge that Irene could bring to New York and New England. Storm surge is forecast to raise water levels by as much as 4 to 8 feet above ground level from the North Carolina/Virginia border northward to Cape Cod. There is a chance that the surge could over-top lower Manhattan’s flood walls and enter the city’s subway system. Such a scenario could result in large business interruption losses. Other vulnerable low-lying areas in the state include Coney Island and Manhattan Beach in Brooklyn, where evacuations are still urgently taking place. Low-lying towns along the Connecticut coastline and Rhode Island’s Buzzards Bay are also at risk.
It should be noted that the degree and extent of storm surge along the most populated stretches of the coast are highly uncertain at this stage. Because Irene is such a large and persistent storm, surge levels could be higher than might be expected from Category 1 wind speeds. It should also be noted that insured losses will be highly sensitive to how surge levels ultimately materialize.
With rainfall amounts of 6 to 10 inches expected across the region, flooding is another significant threat. River flood and flash flood watches and warnings have been issued for much of New England, as far north as northwest Maine. The heavy precipitation and Irene’s large wind field could also result in widespread damage from downed trees.
AIR continues to closely monitor Irene’s progress and will provide updates as warranted, and contingent upon storm conditions in the Boston area tomorrow (Sunday, August 28).
AIR will be announcing estimated insured losses for the U.S. in the coming days.