Flash Flood — Boise, Idaho

2025-06-11 · near Lowman, Boise, Idaho

Event narrative

A Forest Service official reported that Forest Service Road 555 (Scott Mtn Rd) was washed out as a result of a stream of water ran over the road. The radar estimated rainfall total was 0.3 inches, with a maximum estimated rainfall rate of 2 inches per hour. Timing was estimated from peak hydrophobic unit flow.

Wider weather episode

On June 11th, a shortwave trough crossed across southwest Idaho aiding in thunderstorm development. RAP Mesoscale Analysis showed precipitable water values between 0.8 - 1 inch, around the climatological 95th percentile. With this moisture, heavy rain over burn scars was a primary hazard with storms that developed.

View location on OpenStreetMap → (44.1661, -115.7259)

Source: NOAA Storm Events Database, event_id 1274985. Narrative written by the NWS forecast office that issued the report.