Debris Flow — Chelan, Washington

2018-05-17 · near Malaga, Chelan, Washington

Event narrative

Heavy rain from thunderstorms during the evening of May 17th resulted in a debris flow of rocks and mud onto the Malaga-Alcoa Highway betrween mileposts 10 and 12.

Wider weather episode

Thunderstorms developed over the east slopes of the Cascades and the Columbia Basin in a rich feed of wrap around moisture from an upper low over Oregon during the night of May 17th. These storms dumped a general quarter to half inch of rain over most of the western basin, but individual cells locally produced higher amounts with Ephrata measuring 0.72 inches. Local flash flooding and debris flows were noted from these storms.

View location on OpenStreetMap → (47.3400, -120.1200)

Source: NOAA Storm Events Database, event_id 758689. Narrative written by the NWS forecast office that issued the report.