Heavy Snow — Cascades of Snohomish and King Counties, Washington

2021-02-04 to 2021-02-05 · Cascades of Snohomish and King Counties, Washington

Event narrative

Light snow began to fall around Stevens Pass and the nearby Central Cascades around day break on February 4th and began to pick up in intensity around 6PM. From the evening hours of February 4th to daybreak on February 5th ( a 12 hour period), around 14 inches of new snow fell. Snow then tapered through the remaining hours of the morning on the 5th.

Wider weather episode

A strong shortwave trough of low pressure passed across Western Washington at the beginning of February and then began depart the area on February 4th. In the shortwave's wake was the development of an unstable atmosphere, with strong flow aloft and lingering upper level divergence in the left exit region of a strong jet. This resulted in heavy snowfall over the mountains from February 4 through February 5, affecting mostly the Central Cascades.

Source: NOAA Storm Events Database, event_id 945314. Narrative written by the NWS forecast office that issued the report.