Heavy Snow — East Slopes Northern Cascades, Washington

2020-12-20 to 2020-12-21 · East Slopes Northern Cascades, Washington

Event narrative

Numerous locations across the Methow Valley, in Okanogan County, received heavy snowfall in this winter storm. There were reports of 24 hour accumulations of 7 to 9 inches, as well as 48 hour reports of 12 to 14 inches.

Wider weather episode

A new winter system moved in as a trough dropped into the Pacific Northwest on December 21st. With the accompanying atmospheric river, this system had substantial moisture with it bringing a wet and windy day ahead. Most of Eastern Washington was still too warm for snow, but there was moderate snowfall in the east Cascade slopes. Throughout the remainder of the region, locations received 24 hour rainfall totals up to 0.5 - 1.0. In addition to wet conditions, the evening of the 21st into the early morning hours of the 22nd were windy. The strongest winds were in far Eastern Washington, from Spokane to Pullman, and Cascade slopes.

Source: NOAA Storm Events Database, event_id 933511. Narrative written by the NWS forecast office that issued the report.