Heavy Snow — Cascades of Snohomish and King Counties, Washington

2021-02-22 · Cascades of Snohomish and King Counties, Washington

Event narrative

Snow began in the Central Cascades on February 21st and peaked in intensity on February 22nd. In a 12 hour period spanning from 6am to 6pm on February 22nd, around 15 inches of new snow fell across Stevens Pass. Snow then tapered into the night, with a few more inches reported by sunrise on the 23rd. In total, around 19 inches of new snow fell in a 24 hour period spanning from 6am on the 22nd to 6am on the 23rd.

In addition to heavy snowfall, the presence of high avalanche danger amidst an unstable snowpack caused WSDOT to to close all major cross-cascade highways, including US 2 over Stevens Pass and I-90 over Snoqualmie Pass the evening of February 21st through the morning of February 22nd. After opening the morning of the 22nd, additional snowfall then led WSDOT to re-close US 2 over Stevens Pass. Avalanches were reported near the Pass after the highway closed, along with reports of snow slides blocking the road on the east side of the Pass between MP 58 and 85. The highway did not reopen until February 23rd.

Wider weather episode

A compact shortwave trough, aided by very strong flow aloft passed across Western Washington on February 22, bringing with it another round of heavy snowfall to the Cascades.

Source: NOAA Storm Events Database, event_id 945333. Narrative written by the NWS forecast office that issued the report.