Freezing Fog — Frank Church Wilderness, Idaho

2020-12-20 · Frank Church Wilderness, Idaho

Event narrative

On December 20th dense freezing fog and freezing drizzle caused black ice to form on State Highway 75 between Idaho 21 and Squaw Canyon Road south of Clayton. It covered a 37 mile stretch from mile post 191 to mile post 218. All lanes were blocked and the road was closed by 6 am on the 20th.

Source: NOAA Storm Events Database, event_id 929721. Narrative written by the NWS forecast office that issued the report.