A warm front ahead of a developing coastal low pressure system positions itself over the area late on December 17th and into December 18th. As the low pressure intensified and approached, significant amounts of moisture focused along the warm front ahead of the coastal low resulting in widespread areas of heavy rainfall that occurred over a 12-18 hour period. PWATs were 1.5-1.7 inches which were near record values. A widespread 2-5 inches of rain fell over the area. This resulted in many areas of flash flooding as well as significant rises in rivers.

Flash Flood in ROCKLAND, NEW YORK
From 18-DEC-23 04:55:00 to 18-DEC-23 05:25:00 (EST-5)
Location: CENTRAL NYACK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding and road closure on NY 303 in both directions in Clarkstown.

Flash Flood in ROCKLAND, NEW YORK
From 18-DEC-23 05:07:00 to 18-DEC-23 05:37:00 (EST-5)
Location: WILLOW GROVE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding and road closure on Palisades interstate Parkway both directions at Exit 14 Willow Grove Road. All lanes closed.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 06:04:00 to 18-DEC-23 06:34:00 (EST-5)
Location: ELMSFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding on Saw Mill River Parkway Southbound at Exit 21W Frontage Road. All Lanes Closed.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 07:01:00 to 18-DEC-23 07:31:00 (EST-5)
Location: TUCKAHOE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding and road closure on Bronx River Parkway Northbound at Exit Sprain Brook Parkway. All lanes closed.

Flash Flood in ROCKLAND, NEW YORK
From 18-DEC-23 07:08:00 to 18-DEC-23 07:38:00 (EST-5)
Location: CENTRAL NYACK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Flooding and road closure on NY 303 both directions in area on NY 59. All lanes closed.

Flash Flood in PUTNAM, NEW YORK
From 18-DEC-23 07:26:00 to 18-DEC-23 07:56:00 (EST-5)
Location: NELSONVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding on NY 9D both directions near Fair Street. All lanes closed.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 08:19:00 to 18-DEC-23 08:49:00 (EST-5)
Location: KITCHAWAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding and ramp closure on Taconic State parkway Southbound ramp to Exit 11 NY 134. All lanes blocked.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 08:22:00 to 18-DEC-23 08:52:00 (EST-5)
Location: WOODLANDS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding on Saw Mill River Parkway southbound approaching Exit 18 Cyrus Field Road. All lanes closed.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 08:52:00 to 18-DEC-23 09:22:00 (EST-5)
Location: ELMSFORD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding on US 9 southbound at Old Country Road. All lanes closed.

Flash Flood in WESTCHESTER, NEW YORK
From 18-DEC-23 10:00:00 to 18-DEC-23 10:30:00 (EST-5)
Location: DUNWOODIE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Video of palmer road flooded in the Bronx. Road impassable.

Flash Flood in ORANGE, NEW YORK
From 18-DEC-23 09:29:00 to 18-DEC-23 09:59:00 (EST-5)
Location: CENTRAL VLY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Northbound entrance ramp to I 87 at exit 16 in Harriman closed due to flooding.