Winter Storm — Northern Grafton, New Hampshire

2021-02-01 to 2021-02-02 · Northern Grafton, New Hampshire

Event narrative

Snow moved into the area on the evening of the 1st and continued through the morning hours on the 2nd. The bulk of the accumulation came with moderate to heavy snow in the mesoscale snow band as it moved north through the White Mountains. Snow continued into the evening in waves as additional moisture was pulled inland from the Gulf of Maine and forced over the higher terrain. Snowfall ranged from 4 to 12 inches, with the lowest amounts in the Pemigewasset Valley where persistent banding remaining south and downsloping helped to cut down totals.

Wider weather episode

Low pressure moved into the Ohio Valley on the 31st, where it began to encounter resistance from high pressure anchored over James Bay. As the upper trough continued east, secondary low pressure began to develop along the warm front near the Outer Banks. This new low pressure center deepened and quickly occluded south of Long Island by midday on the 1st. It meandered south of Long Island into the morning of the 2nd before finally moving northeastward into the Gulf of Maine during the latter half of the day. During the occlusion phase a strong, pivoting mesoscale band of heavy snow impacted parts of the Mid Atlantic, while the northeastern extension of the band remained rather progressive lifting through New England. The heavy snow ended early on the 2nd but snow and sleet continued through the day for much of the northern half of New Hampshire. Precipitation tapered off late on the 2nd. Key Impacts: transportation delays, traffic accidents, heavy snow.

Source: NOAA Storm Events Database, event_id 934003. Narrative written by the NWS forecast office that issued the report.