A wave of low pressure developed along the Middle Atlantic coast during Thursday November 15, 2018. The low was associated with a closed upper level trough across the Midwest. As the trough translated eastward into Friday November 16, 2018, the low pressure moved up the northeast coast. The antecedent air mass ahead of the low was cold and dry for the middle of November with temperatures during the morning and afternoon of November in the upper 20s and low 30s.  The moisture associated with the trough and low pressure was able to produce moderate to heavy bands of snow as the precipitation began across the entire Tri-State area due to the cold air in place. Once the low drew warmer air from the south, the precipitation gradually changed to a wintry mix and then plain rain, especially for the New York City metro and Long Island.  The moderate to heavy wet snowfall significantly impacted the evening rush hour with 1-2 inch per hour snowfall rates.  Hundreds of trees, tree limbs, and branches were brought down by the weight of the snow, including over 100 trees alone in the  New York City metro. Numerous accidents were reported along with a 20 car accident on the George Washing Bridge. Many motorists were stranded on roads across the city until the early morning hours the next day. The Long Island Railroad had delays and cancellations and there were over 1,000 flights cancelled at the New York City metro airports (Kennedy, La Guardia, and Newark).

Winter Storm in BRONX, NEW YORK
From 15-NOV-18 14:00:00 to 15-NOV-18 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS and the public reported 6 to 7 inches of snow. There were numerous accidents across roads and highways in the Bronx with many motorists stranded for hours. Snowfall rates at nearby La Guardia airport were around 1 inch per hour at times.

Winter Storm in KINGS (BROOKLYN), NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, New York City OEM CERT, and the Broadcast Media reported 4 to 6 inches of snow. Impacts were widely felt across Brooklyn with major disruption to the evening commute and many trees and limbs down due to the weight of the heavy wet snow. Nearby Kennedy airport reported 1 inch per hour snowfall rates at times during the evening commute.

Winter Storm in NORTHERN QUEENS, NEW YORK
From 15-NOV-18 14:00:00 to 15-NOV-18 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The FAA Contract Observer at La Guardia Airport reported 4.7 inches of snow. Trained spotters and the public reported 4 to 6 inches of snow. Impacts were widely felt across Northern Queens with major disruption to the evening commute and many trees and limbs down due to the weight of the heavy wet snow. Snowfall rates at nearby La Guardia airport were around 1 inch per hour at times during the evening commute.

Winter Storm in SOUTHERN QUEENS, NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The FAA contract observer at Kennedy Airport reported 4.8 inches of snow. Trained spotters, NYC OEM CERT, CoCoRaHS, and Amateur Radio reported 3 to 5 inches of snow. Trained spotters, New York City OEM CERT, and the Broadcast Media reported 4 to 6 inches of snow. Impacts were widely felt across southern Queens with major disruption to the evening commute and many trees and limbs down due to the weight of the heavy wet snow. Kennedy airport reported 1 inch per hour snowfall rates at times during the evening commute.

Winter Storm in RICHMOND (STATEN IS.), NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The public reported 4 inches of snow in Dongan Hills. Impacts were widely felt across Staten Island with major disruption to the evening commute and many trees and limbs down due to the weight of the heavy wet snow. Nearby Kennedy airport reported 1 inch per hour snowfall rates at times during the evening commute.

Winter Storm in NEW YORK (MANHATTAN), NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The Official NWS Observation at Central Park reported 6.4 inches of snow. NYC OEM CERT and CoCoRaHS reported 4 to 6 inches of snow. Impacts were widely felt across Manhattan with major disruption to the evening commute and about 100 trees were downed due to the weight of the heavy wet snow. Nearby Kennedy and La Guardia airports reported 1 inch per hour snowfall rates at times during the evening commute.

Winter Weather in NORTHERN NASSAU, NEW YORK
From 15-NOV-18 14:00:00 to 15-NOV-18 20:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, social media, and the public reported 4 to 6 inches of snow.

Winter Weather in SOUTHERN NASSAU, NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, Amateur radio, and CoCoRaHs reported 4 to 5 inches of snow.

Winter Weather in NORTHEAST SUFFOLK, NEW YORK
From 15-NOV-18 14:00:00 to 15-NOV-18 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, Social Media, and the public reported 2 to 5 inches of snow.

Winter Weather in SOUTHEAST SUFFOLK, NEW YORK
From 15-NOV-18 14:00:00 to 15-NOV-18 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, social media, and the public reported 2 to 5 inches of snow.

Winter Weather in SOUTHWEST SUFFOLK, NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The FAA observer at Islip Airport reported 4 inches of snow. Trained spotters, an NWS Employee, and CoCoRaHS reported 3 to 5 inches of snow.

Winter Weather in NORTHWEST SUFFOLK, NEW YORK
From 15-NOV-18 13:30:00 to 15-NOV-18 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The FAA observer at nearby Islip Airport reported 4 inches of snow. Trained spotters, an NWS Employee, and CoCoRaHS reported 3 to 5 inches of snow.

Winter Storm in ORANGE, NEW YORK
From 15-NOV-18 15:30:00 to 16-NOV-18 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported 9 to 18 inches of snow. Many reports were between 10 to 12 inches with a isolated reports over a foot. A spotter in Mount Hope reported 18 inches of snow.

Winter Storm in PUTNAM, NEW YORK
From 15-NOV-18 13:30:00 to 16-NOV-18 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, Social Media, Broadcast Media, and the public reported 7 to 9 inches of snow.

Winter Storm in ROCKLAND, NEW YORK
From 15-NOV-18 15:00:00 to 16-NOV-18 00:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters, Social Media, and the public reported 5 to 8 inches of snow.

Winter Storm in NORTHERN WESTCHESTER, NEW YORK
From 15-NOV-18 15:00:00 to 16-NOV-18 00:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Social Media, trained spotters, CoCoRaHS, and the public reported 6 to 9 inches of snow.

Winter Storm in SOUTHERN WESTCHESTER, NEW YORK
From 15-NOV-18 15:00:00 to 15-NOV-18 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur Radio and the public reported 5 to 7 inches of snow.