An intensifying storm moved up the Eastern Seaboard from northern Florida on December 17th, to the coastal Mid Atlantic region on the 18th. This storm produced a strong onshore flow on the 18th that combined with high astronomical tides to cause widespread moderate to locally major coastal flooding and beach erosion along the south shore of Long Island during the late morning and afternoon.

Coastal Flood in SOUTHERN NASSAU, NEW YORK
From 18-DEC-23 10:00:00 to 18-DEC-23 15:00:00 (EST-5)
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate to locally major coastal flooding occurred along the south shore of Nassau:
At the Freeport USGS tidal gauge, major floooding of 7.2 ft MLLW occurred at 1236 PM EST. Moderate flooding of 6.5 ft MLLW or more occurred from 1036 AM EST to 130 PM EST.
At the Reynolds Channel tidal gauge, moderate coastal flooding of 7.0 ft MLLW or more occurred from 1148 AM EST to 1236 PM EST, with a peak water level of 7.3 ft MLLW from 1224 PM EST to 1236 PM EST.
At the East Rockaway Inlet USGS tidal gauge, moderate flooding of 7.2 ft MLLW or more occurred from 1118 AM EST to 1242 PM EST, with a peak water level of 7.5 ft from 1206 PM EST to 1224 PM EST.

Coastal Flood in SOUTHWEST SUFFOLK, NEW YORK
From 18-DEC-23 11:00:00 to 18-DEC-23 19:00:00 (EST-5)
Crop damage: 0.00K
Reported by: River/Stream Gage

Major coastal flooding occurred along the south shore of SW Suffolk, and major beach erosion also occurred along the south shore of Fire Island:
At the Watch Hill/Fire Island USGS tidal gauge, major flooding above the threshold of 4.2 ft MLLW occurred from 142 PM EST to 506 PM EST, with a peak water level of 4.7 ft MLLW from 248 PM EST to 342 PM EST. Moderate flooding of 3.7 ft MLLW or more occurred from 1242 PM EST to 612 PM EST.
At the Lindenhurst USGS tidal gauge, major coastal flooding at the threshold of 4.1 ft MLLW occurred from 124 PM EST to 212 PM EST. Moderate flooding of 3.6 ft MLLW or more occurred from 1148 AM EST to 324 PM EST.
At the West Sayville USGS tidal gauge, major coastal flooding of 4.1 ft MLLW or more occurred from 118 PM EST to 518 PM EST, with a peak a peak water level of 4.5 ft MLLW from 300 PM EST to 318 PM EST. Moderate flooding of 3.6 ft MLLW or more occurred from 1148 AM EST to 636 PM EST.

Coastal Flood in SOUTHEAST SUFFOLK, NEW YORK
From 18-DEC-23 09:00:00 to 18-DEC-23 15:00:00 (EST-5)
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate coastal flooding and major beach erosion occurred along the south shore of SE Suffolk:
At the East Moriches USGS tidal gauge, moderate coastal flooding of 5.3 ft MLLW or more occurred from 1130 AM EST to 230 PM EST, with a peak water level of 5.7 ft MLLW from 142 PM EST to 148 PM EST.
At the Montauk NOS tidal gauge, moderate coastal flooding of 4.9 ft MLLW or more occurred from 1100 AM EST to 200 PM EST, with a peak water level of 5.0 ft MLLW 1106 AM EST.

At the Ponquoque USGS tidal gauge, moderate coastal flooding of 5.9 ft MLLW or more occurred from 954 AM EST to 212 PM EST, with a peak water level of 6.5 ft MLLW 1254 PM EST to 100 PM EST.

Coastal Flood in NORTHEAST SUFFOLK, NEW YORK
From 18-DEC-23 14:00:00 to 18-DEC-23 16:00:00 (EST-5)
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate coastal flooding occurred along the shores of NE Suffolk:
At the Orient Harbor USGS tidal gauge, moderate coastal flooding of 5.8 ft MLLW occurred from 236 PM EST to 321 PM EST.

Coastal Flood in SOUTHERN QUEENS, NEW YORK
From 18-DEC-23 11:00:00 to 18-DEC-23 13:00:00 (EST-5)
Crop damage: 0.00K
Reported by: River/Stream Gage

Moderate coastal flooding occurred along the south shore of Queens:
At the Jamaica Bay (Inwood) USGS tidal gauge, moderate flooding above the threshold of 8.5 ft MLLW occurred from 1154 AM to 1230 PM, with a peak water level of 8.6 ft MLLW from 1200 PM EST to 1212 PM EST.
At East Rockaway Inlet, moderate flooding above the threshold of 7.2 ft MLLW occurred from 1118 AM EST to 1224 PM EST, with a peak water level of 7.5 ft MLLW from 1206 PM EST to 1224 PM EST.