Debris Flow — Malheur, Oregon

2025-07-09 · near Borgan, Malheur, Oregon

Event narrative

A thunderstorm passed over the Cow Valley burn scar. Radar estimated hourly QPE ranging from 1.5 to 1.75 inches with the three hourly estimate having a peak of 2.0 to 2.5 inches. The Oregon Department of Transportation reported a debris flow across US 26 between mile markers 249-251, resulting in traffic delays. Timing was estimated using hydrophobic unit streamflow, which peaked at 6-10 cubic meters per second per kilometer squared.

Wider weather episode

On July 9th, an upper level low tracked northeast across eastern Oregon aiding in thunderstorm development. With a dry boundary layer, and marginal precipitable water values, outflow winds were the primary hazard with burn scar flooding a secondary hazard.

View location on OpenStreetMap → (44.2610, -117.5770)

Source: NOAA Storm Events Database, event_id 1281124. Narrative written by the NWS forecast office that issued the report.