Winter Storm — Southern Grafton, New Hampshire

2024-03-09 to 2024-03-10 · Southern Grafton, New Hampshire

Event narrative

Precipitation began as a light mix, especially across the lower elevations and valleys of Grafton County. As heavier precipitation moved into the region, the precipitation type transitioned to snow, which became heavy at times in the higher terrain. In the lowest elevations, warmer temperatures kept snow from accumulating significantly. By the time snow tapered off with a light rain and mix, snowfall totals ranged from 4 inches in the Connecticut River Valley to as much as 6 to 10 inches in the southern White Mountains.

Wider weather episode

High pressure in control on the 9th began to slide northeast through the day as primary low pressure moved through the Great Lakes into southern Canada. A secondary area of low pressure developed over inland areas of the Carolinas. Sustained warm air advection forced a large area of moderate to heavy precipitation up and over the colder near-surface air mass. Light precipitation began as a mix, but in the higher elevations quickly changed to snow, heavy at times. Closer to the ocean, the coastal front progressed inland and snow changed to rain, which also fell heavy at times overnight. Warm air eventually won out, with precipitation ending as a light rain or mix and significant settling of existing snowpack. Strong onshore flow interacted with a high astronomical tide to bring coastal flooding to the Seacoast of New Hampshire.

Source: NOAA Storm Events Database, event_id 1162822. Narrative written by the NWS forecast office that issued the report.