A modest low pressure system developed along the Gulf Coast on the 16th, with secondary development occurring off the Carolinas by the afternoon. An Arctic air mass was in place over New England as a strong high pressure anchored itself in the Saint Lawrence River Valley. Low pressure occluded early on the 17th and slowly tracked south of New England through the day. An intense band of heavy snow moved north into parts of western Maine early in the morning on the 17th and remained nearly stationary into the afternoon. Snowfall rates of 4 to 6 inches per hour and total amounts of 1 to 2 feet were observed at the peak of the event. Dry air and a deamplifying upper trough limited the northward push of heavy snow, leaving a sharp gradient on the poleward edge of accumulating snowfall.

Winter Storm in COASTAL CUMBERLAND, MAINE
From 17-DEC-20 04:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began before sunrise on the 17th. Snow quickly became heavy as an intense band of snow moved into the area. As the band became nearly stationary snowfall rates of 2 to 4 inches per hour were observed for several hours. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 14 and 20 inches.

Winter Storm in COASTAL YORK, MAINE
From 17-DEC-20 02:00:00 to 17-DEC-20 15:00:00 (EST-5)
Reported by: Trained Spotter

Snow began before sunrise on the 17th. Snow quickly became heavy as an intense band of snow moved into the area. While the band became stationary north of the area, as it moved through snowfall rates of 2 to 4 inches per hour were observed. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 10 and 16 inches.

Winter Storm in KNOX, MAINE
From 17-DEC-20 08:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began after sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. While the band became nearly stationary just offshore, snowfall was still occasionally heavy at times. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 8 and 12 inches.

Winter Storm in COASTAL WALDO, MAINE
From 17-DEC-20 08:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began after sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. While the band became nearly stationary just to the south, snowfall was still occasionally heavy at times near Penobscot Bay. Dry air to the north and weakening lift with increasing latitude left a sharp gradient in storm totals north of Route 3. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 6 and 12 inches.

Winter Storm in CENTRAL INTERIOR CUMBERLAND, MAINE
From 17-DEC-20 04:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began before sunrise on the 17th. Snow quickly became heavy as an intense band of snow moved into the area. As the band became nearly stationary snowfall rates of 2 to 4 inches per hour were observed for several hours. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 10 and 20 inches.

Winter Storm in INTERIOR CUMBERLAND HIGHLANDS, MAINE
From 17-DEC-20 05:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began before sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. While the band became stationary just south of the area, snow was still heavy at times. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 8 and 12 inches.

Winter Storm in SAGADAHOC, MAINE
From 17-DEC-20 08:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began after sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. The band became nearly stationary and started to weaken over the area, with snowfall rates in excess of 1 inch per hour at times. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 12 and 15 inches.

Winter Storm in LINCOLN, MAINE
From 17-DEC-20 08:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began after sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. The band became nearly stationary and started to weaken over the area, with snowfall rates in excess of 1 inch per hour at times. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 12 and 15 inches.

Winter Storm in NORTHERN OXFORD, MAINE
From 17-DEC-20 05:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began before sunrise on the 17th. Snow became moderate to heavy as an intense band of snow moved towards the area. While the band became stationary just south of the area, snow was still heavy at times near Route 302. Dry air to the north and weakening lift with increasing latitude left a sharp gradient in storm totals south of Route 2. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 2 inches near Route 2 and 18 inches south of Fryeburg.

Winter Storm in ANDROSCOGGIN, MAINE
From 17-DEC-20 07:00:00 to 17-DEC-20 16:00:00 (EST-5)
Reported by: Trained Spotter

Snow began around sunrise on the 17th. Snow quickly became moderate to heavy as an intense band of snow moved towards the area. While the band became stationary just south of the area, snow was still heavy at times. Dry air to the north and weakening lift with increasing latitude left a sharp gradient in storm totals north of Turner. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 3 inches near Livermore Falls and 15 inches south of I-95.

Winter Storm in INTERIOR YORK, MAINE
From 17-DEC-20 02:00:00 to 17-DEC-20 15:00:00 (EST-5)
Reported by: Trained Spotter

Snow began early in the morning on the 17th. Snow quickly became heavy as an intense band of snow moved into the area. As the band became nearly stationary snowfall rates of 2 to 4 inches per hour were observed for several hours. A weakening trough aloft quickly brought an end to snow by mid afternoon. Snowfall totals ranged between 12 and 24 inches.