Thunderstorm Wind — Benewah, Idaho

2011-12-29 · near St Maries, Benewah, Idaho

Event narrative

The St Maries COOP reported a tree had fallen onto power-lines in the Benewah Valley due to strong wind gusts associated with thunderstorms between 1230 AM PST and 100AM PST.

Wider weather episode

On the evening of the 28th into the early morning hours of the 29th, a low-level jet developed over the Idaho Panhandle ahead of a strong low pressure system tracking along the Washington / Canadian Border. Through midnight, the strong low-level winds remained decoupled from the valley floors with high wind gusts measured only along exposed ridgetops. Around midnight, a line of thunderstorms developed along the trailing cold front. A combination of descending air within the thunderstorm downdrafts along with terrain channeling was thought to be responsible for mixing the stronger winds aloft down to some valley locations within the Central Panhandle Mountains of Idaho. There were two reports of large trees toppled by these winds. Wind gusts within the zone ranged from 30 to 60 miles per hour with gusts near 60 miles per hour thought to be present where the trees were downed.

View location on OpenStreetMap → (47.3200, -116.5800)

Source: NOAA Storm Events Database, event_id 353251. Narrative written by the NWS forecast office that issued the report.