Winter Weather — Southern Grafton, New Hampshire

2022-02-27 · Southern Grafton, New Hampshire

Event narrative

Snow squalls crossed the Upper Valley between 5:00 pm and 6:00 pm. The Lebanon Municipal Airport observed a visibility of 1/4 mile and a wind gust of 26 knots at 5:55 pm, and the Plymouth Municipal Airport observed a visibility of 1/4 mile and a wind gust of 27 knots also at 5:55 pm.

Wider weather episode

An arctic cold front drove through the Northeast on the evening of the 27th. The upper shortwave trough was rapidly transitioning to negatively tilted and at its strongest forcing for ascent as it crossed the local area. The temperatures at 850 hPa dropped from around -10 degrees Celsius in the evening to -19 degrees Celsius by morning. Low level lapse rates were very steep, approaching 9 degrees Celsius per kilometer. This led to some small amounts of low level CAPE, which considering the time of year were quite impressive. The result was a well organized line of snow squalls that affected the majority of the local forecast area, bringing widespread travel impacts due to dangerous short term blizzard conditions.

Source: NOAA Storm Events Database, event_id 1009430. Narrative written by the NWS forecast office that issued the report.