Winter Storm — Northern Coos, New Hampshire

2019-12-30 to 2019-12-31 · Northern Coos, New Hampshire

Event narrative

Snow moved in late on December 29th. Drier air from the northeast pushed snow back to the southwest for a time early on the 30th and snow came to an end briefly. A band of moderate to heavy to snow then developed and then stalled overhead. Snow lightened up around midday but light snow continued into the morning of the 31st. Snow and sleet totals ranged from 6 inches in southeast downslope areas near the Connecticut River to 12 inches in the higher terrain.

Wider weather episode

On December 29th a primary low pressure moved into the Upper Midwest with a warm front draped off to the east. Air rising over the warm front brought precipitation into New England late on the 29th as a mix of freezing rain, sleet, and snow with a relatively mild air mass in place. The feed of colder air strengthened through the 30th with significant amounts of mixed precipitation occurring over the southwestern part of New Hampshire. A nearly stationary band of moderate to heavy snow set up over the eastern part of the state. As the upper trough approached in the afternoon thunderstorms developed south of the warm front and moved across it into the cold air. Thunder was reported with freezing rain and sleet across southern New Hampshire before the convection weakened. It was around this time that precipitation began to change over to all snow. Light snow continued into the 31st as secondary low pressure developed south of New England.

Source: NOAA Storm Events Database, event_id 864025. Narrative written by the NWS forecast office that issued the report.