Winter Storm — Southern Grafton, New Hampshire

2021-12-18 to 2021-12-19 · Southern Grafton, New Hampshire

Event narrative

Snow overspread the southern White Mountains by midday on the 18th. Snow became moderate in the evening but otherwise remained light for the duration of the storm. Snow tapered off early in the morning on the 19th, finally ending as a couple of waves of light snow enhanced by upsloping winds over the mountains. Storm total snowfall ranged from 6 to 8 inches.

Wider weather episode

A frontal wave developed in the lower Ohio River Valley on the 18th and lifted northeastward towards Lake Erie. Cold air damming remained entrenched and secondary low pressure began developing farther east along the warm front, south of New England. This low slowly strengthened as it moved east northeastward just over the tip of Cape Cod. While snow overspread the entire area, the mid level warm front was able to advance into southern New Hampshire and changed precipitation over to sleet and freezing rain. The heaviest snowfall ran roughly west to east through the Lakes Region.

Source: NOAA Storm Events Database, event_id 994336. Narrative written by the NWS forecast office that issued the report.