Coastal Flood — Southeast Suffolk, New York

2012-10-28 to 2012-10-30 · Southeast Suffolk, New York

Event narrative

Coastal communities along Southeast Suffolk County experienced 2 to 3 successive tidal cycles with at least moderate coastal flooding, with 2 of those tidal cycles well above major flood thresholds. The peak of this surge occurred Monday Night as Sandy made landfall in Southern New Jersey, with widespread major coastal flooding occurring along the Great South Bay, Atlantic Ocean and Peconic and Gardiners Bays. Peak storm tides surpassed all previously documented high water marks, including the October 31, 1991 and December 11, 1992 nor'easters and the recorded peaks from Hurricane Irene in 2011.

The storm tide levels along the Great South Bay, Gardiners Bay and Atlantic Ocean resulted from a peak storm surge of about 5 to 6 feet that coincided with normal high tides, while surge was around 7 to 9 feet along the Peconic Estuary. This resulted in up to 2 to 5 feet of inundation of communities in and along Great South Bay, Atlantic Ocean and Peconic and Gardiners Bay. The majority of coastal communities were inundated several blocks inward from the shoreline. Areas of major residential damage were experienced across low lying areas such as Mastic and Moriches. A few feet of inundation of streets and neighboring properties also occurred in low lying areas of Southampton, Quogue, Sag Harbor, and Riverhead. In Riverhead, surge up the Peconic River caused the closing of the traffic circle on Peconic Avenue at the intersection of CR 104 and CR 63.

Additional major damage was experienced along the barrier beach communities, where the surge was amplified by the runup and setup from 15 to 20 foot breakers along the Atlantic Ocean coast. Several homes along Dune Road experienced major damage between Moriches Inlet and Shinnecock Inlet. A complete breach of the barrier island occurred just west of Cupsogue Beach and East of Moriches Inlet. In the Montauk area parks, severe erosion and flooding occurred throughout all beaches, with significant bluff erosion.

One fatality was directly attributed to the storm surge and high surf in southeastern suffolk county.

Wider weather episode

Post Tropical Storm Sandy was the costliest natural disaster in Southeast New York.

Tropical Storm Sandy formed in the Caribbean Sea on October 22. After drifting slowly southwest on October 23, Sandy turned to the north and intensified to a hurricane on October 24, just before making landfall in Jamaica. Hurricane Sandy continued to the north and intensified to a strong category two hurricane before making landfall again in Cuba shortly after Midnight EDT on the 25th. Hurricane Sandy emerged on the other side of Cuba during the morning of the 25th and proceeded to drift northwest as a category one or two hurricane as it moved through the Bahamas on the 25th and 26th. Overnight on the 26th, Hurricane Sandy (Category 1) started to move toward the north northeast, a motion that continued into the evening of the 28th. From there, Sandy's motion became driven by two factors. An anomalously strong blocking ridge over the Canadian Maritimes prevented Sandy from escaping to the east. Simultaneously, an approaching and deepening extratropical trough was about to capture Sandy. The combination of the two, turned Sandy to the north overnight on the 28th and then to the northwest on the 29th.

As Sandy continued to move northwest and interact with the mid latitude trough, its interaction continued to make it less tropical, but did not weaken it much. Sandy continued to make a harder turn to the left (west) and made landfall in Atlantic County as a post tropical storm in Brigantine City just north of Atlantic City at 7:30 p.m. EDT on the 29th. The estimated minimum central pressure was 945 millibars. The lowest recorded central pressure was 945.6 millibars at the Atlantic City Marina at 7:34 p.m. EDT.

Record breaking high tides and wave action was combined with sustained winds of 40 to 60 mph and wind gusts of 80 to 90 mph.

These extreme conditions resulted in at least 60 deaths and widespread property damage of at least 42 billion dollars.

Emergency managers recommended mandatory evacuations of more than 1/2 million people that lived in low lying areas. Widespread significant power outages of more than 2 million lasted up to 2 weeks.

Source: NOAA Storm Events Database, event_id 421617. Narrative written by the NWS forecast office that issued the report.