Heavy Snow — Cascades of Snohomish and King Counties, Washington

2021-12-10 to 2021-12-13 · Cascades of Snohomish and King Counties, Washington

Event narrative

Snow began during the afternoon of December 10 and quickly increased in intensity, particularly over Stevens Pass, by the morning hours of December 11. In about a 24 hour period, almost 20 inches of new snow fell. Snow then continued into the 12th, with about another foot of accumulation. Snow then tapered by the afternoon hours of the 13th, with a few more inches of snow accumulations by then.

Wider weather episode

A strong storm/frontal system moved across Western Washington Dec 10-11, bringing with it heavy mountain snow and high winds. In the wake of the frontal system, an upper level trough moved into the region, keeping for unstable and unsettled weather across the area through the 13th.

Source: NOAA Storm Events Database, event_id 998610. Narrative written by the NWS forecast office that issued the report.