Debris Flow — Chelan, Washington

2019-07-02 to 2019-07-09 · near Manson, Chelan, Washington

Event narrative

Heavy rain on Slide Ridge above South Lakeshore Drive near Chelan washed mud and debris across the road to a depth of 10 to 12 feet in places. The road was closed for a week while highway crews cleared the road and stabilized the hill side.

Wider weather episode

During the afternoon of July 2nd numerous slow moving thunderstorms containing heavy rain formed near the center of an upper level low pressure over the western Columbia Basin and the east slopes of the Cascade Mountains. A rich moisture feed wrapping around this upper low pressure allowed some of these storms to produce heavy rainfall over limited areas. A spotter near Waterville reported 1.29 inches of rain from a series of thunderstorms training through the area. Several reports of flash flooding were received from the region with multiple roads blocked by flowing water, mud and rocks.

View location on OpenStreetMap → (47.9066, -120.2195)

Source: NOAA Storm Events Database, event_id 834015. Narrative written by the NWS forecast office that issued the report.