Heavy Snow — Upper Columbia Basin, Washington

2020-01-10 · Upper Columbia Basin, Washington

Event narrative

The observer at Ritzville recorded 4.2 inches of new snow accumulation.

Wider weather episode

The third week of January brought very active winter weather to the Inland Northwest as a series of surface low pressures tracked along a stalled arctic air mass boundary laying near or over eastern Washington and north Idaho. Occasional feeds of Pacific moisture directed into this storm track lead to periodic heavy accumulations of snow across the region through the week. During the whole week of repeated snow storms many northern valley locations received 2 to 3 feet of snow accumulation with mountain ski resorts reporting 4 to 5 feet of fresh powder.

The first surface low pressure system tracked through northern Washington and Idaho on January 11th and 12th. A stationary front followed by a cold front produced a period of accumulating snow across the region. Only the lowest elevations of the Columbia River and Okanogan River Valleys received minor snow accumulations in the precipitation shadowed lee of the Cascades.

Over the East Slopes of the Cascades a persistent Puget Sound Convergence Zone after the cold front passage became focused on the Stevens Pass area for an extended period of time. Stevens Pass recorded 33 inches of snow during this storm. Highway 2 had to be closed at Stevens Pass due to multiple traffic accidents. The BNSF railway line was closed across the pass due to hundreds of trees toppled by heavy wet snow.

Elsewhere across northeast Washington and north Idaho over 25,000 customers lost power due to snow laden trees toppling into power lines.

Source: NOAA Storm Events Database, event_id 870911. Narrative written by the NWS forecast office that issued the report.