Coastal Flood — Northwest Suffolk, New York

2012-10-29 to 2012-10-30 · Northwest Suffolk, New York

Event narrative

Coastal communities along Northwest Suffolk County experienced two successive tidal cycles with at least moderate coastal flooding. The peak of this surge occurred Monday Night as Sandy made landfall in Southern New Jersey, with widespread record coastal flooding occurring along Western Long Island Sound.

Peak storm tides surpassed water levels from the October 31, 1991 and December 11, 1992 nor'easters and the recorded peak surges from Hurricane Irene in 2011. The record storm tide levels in Western Long Island Sound resulted from a peak storm surge of about 8 to 10 feet that coincided with normal high tides.

These storm tides resulted in up to 2 to 4 feet of inundation along vulnerable shoreline communities of Western Long Island, with the greatest inundation along the low lying shoreline areas of Huntington Bay, Northport Bay, Stony Brook Harbor, Port Jefferson Harbor and Mt. Sinai Harbor.

In Sunken Meadow State Park, the largest amount of sand ever deposited was observed. While in Caumsett State Park, extensive erosion and bluff erosion was observed.

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 421590. Narrative written by the NWS forecast office that issued the report.