Winter Storm — Coastal Waldo, Maine

2020-12-17 · Coastal Waldo, Maine

Event narrative

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.

Wider weather episode

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.

Source: NOAA Storm Events Database, event_id 926307. Narrative written by the NWS forecast office that issued the report.