Debris Flow — Multnomah, Oregon

2018-12-11 to 2018-12-12 · near Bonneville, Multnomah, Oregon

Event narrative

Rain falling on the Eagle Creek burn scar caused a landslide that blocked exit 41 on I-84 for several days.

Wider weather episode

A warm front moved through northwest Oregon the morning of December 11th, lifting snow levels up high enough for precipitation to fall as rain ahead of the cold front that afternoon. Surface temperatures on Mt Hood, however, were still below freezing so rain froze on contact with surfaces and created a layer of ice. Once the cold front passed, snow levels dropped, changing precipitation back over to snow, and 10 inches of snow fell overnight December 11 to December 12. Rain falling at lower elevations also caused a landslide in the Columbia Gorge the night of December 11th.

View location on OpenStreetMap → (45.6317, -121.9545)

Source: NOAA Storm Events Database, event_id 798978. Narrative written by the NWS forecast office that issued the report.