Debris Flow — Pend Oreille, Washington

2014-03-09 · near Metaline, Pend Oreille, Washington

Event narrative

The southbound lane of State Route 31 at milepost 11 was blocked by a combination of mud and large rocks. Time of the debris flow was estimated.

Wider weather episode

An upper level low pressure system in the Gulf of Alaska late on March 8th into March 9th directed a slow north to south sagging atmospheric river across the area. The origins of this atmospheric river were from off of the Islands of Hawaii. This resulted in abnormally high moisture content for early to mid-March. This was a very mild weather pattern with precipitation falling as rain even over the highest mountain peaks. Moderate to heavy rain was reported in the Northeast Mountains, especially for areas closer to the Idaho border.

View location on OpenStreetMap → (48.8324, -117.4027)

Source: NOAA Storm Events Database, event_id 505266. Narrative written by the NWS forecast office that issued the report.