Overview
A slow-moving nor'easter battered the coastline from New Jersey to New England over the weekend of Sept. 26 and 27, pushing tidal flooding into shore communities through four consecutive high tides, knocking out power to more than 100,000 customers, and producing a hurricane-force gust on eastern Long Island.
The storm tracked through some of the most concentrated coastal exposure in the country. Cotality data show that roughly 1.04 million homes across New Jersey, New York, Connecticut, Rhode Island, and Massachusetts sit at moderate or greater risk of storm surge damage, representing about $518 billion in reconstruction cost value.
The storm, which began delivering coastal flooding to the mid-Atlantic late last week, is forecast to drift away from the coast on Monday, Sept. 28, with one more elevated high tide before conditions improve.
A persistent storm on back-to-back high tides
The National Weather Service in Mount Holly kept a Coastal Flood Warning in effect for the entire New Jersey and Delaware coastline through Sunday afternoon. The warning called for 2 to 3 feet of inundation above ground level at the peak, easing to 1 to 2 feet by Sunday, along with breaking waves of up to 12 feet, significant beach erosion, and possible dune breaching.
The warning's tide tables placed Sandy Hook, Atlantic City, Ocean City, Cape May, Barnegat Light, and Lewes, Delaware, at major flood stage for Saturday morning's high tide and at moderate flood stage for the two tides that followed. Sandy Hook was forecast near 7.9 feet above mean lower low water on Saturday evening and 7.7 feet Sunday morning, roughly 2 to 2.5 feet above normal.
Wind was the second hazard impacting the area. The National Weather Service in New York logged a peak gust of 81 mph at Montauk Point and 71 mph at Stony Brook, with gusts of 61 to 67 mph at Eatons Neck, Baiting Hollow, and Farmingdale Airport. Gusts reached 56 mph at Kennedy Airport and Bridgeport, Connecticut, and 55 mph at Groton, Connecticut.
Rainfall was heaviest in southeastern Massachusetts, where the National Weather Service in Boston recorded 7.33 inches at Acushnet, 7.11 inches at Camp Edwards on Cape Cod, 6.90 inches at Blue Hills in Milton, and 5.51 inches at West Tisbury on Martha's Vineyard through Sunday evening. The National Weather Service office in Upton on Long Island measured 5.33 inches of rain, several Rhode Island stations topped 4 inches, and more than 4 inches was also reported in parts of New Jersey.
Impact to homes, power, and travel
Flooding was repetitive rather than catastrophic. Residents in Sea Bright and Long Beach Island, New Jersey, described the worst tidal flooding in about a decade, with basements and garages filling on each high tide and floodwater entering ground-floor businesses. In Howard Beach, Queens, streets carried several inches of water.
Falling trees damaged homes and utility poles on Long Island. At the peak on Sunday, well over 100,000 customers were without power across the Northeast and mid-Atlantic, concentrated in coastal counties from New Jersey to Connecticut. Additionally, more than 250 flights were canceled at Boston Logan International Airport.
"Homeowners in Sea Bright credited post-Sandy elevation requirements with limiting damage, an early indication that the mitigation investments made after 2012 paid off in this event," said Cotality Chief Scientist Howard Botts. "This storm did not approach Sandy's scale, but it could be the first of several fall nor'easters as an El Niño pattern reshapes the season, and each one lands on beaches and dunes that the last one weakened."
What this means for insurers
The storm tracked through some of the most concentrated coastal exposure in the country. Cotality data show that roughly 1.04 million homes across New Jersey, New York, Connecticut, Rhode Island, and Massachusetts sit at moderate or greater risk of storm surge damage, representing about $518 billion in reconstruction cost value (RCV). The exposure breaks down as follows:
By state
• New York: about 418,000 homes, $227 billion RCV
• New Jersey: about 363,000 homes, $166 billion RCV
• Massachusetts: about 166,000 homes, $80 billion RCV
• Connecticut: about 62,000 homes, $32 billion RCV
• Rhode Island: about 27,000 homes, $13 billion RCV
By metro area
• New York-Newark-Jersey City: about 632,000 homes, $329 billion RCV
• Boston-Cambridge-Newton: about 129,000 homes, $57 billion RCV
In the counties where flooding was most persistent
• Ocean County, New Jersey: about 91,000 homes, $46 billion RCV
• Nassau County, New York: about 85,000 homes, $58 billion RCV
• Suffolk County, New York: about 68,000 homes, $46 billion RCV
• Monmouth County, New Jersey: about 43,000 homes, $24 billion RCV
Losses from this event will fall primarily to the National Flood Insurance Program and private flood carriers for tidal inundation, and to homeowners policies for wind damage from fallen trees and for food spoilage and other outage-related claims. Repetitive-loss properties along the Jersey Shore and the South Shore of Long Island are the segment to watch, particularly if additional nor'easters follow this fall on already eroded beaches and weakened dunes.
Cotality will continue monitoring this event and may provide updates when available.
