Upper Slate River

CB Avalanche CenterCBAC Observations

Date of Observation: 10/27/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Purple Ridge area

Observed avalanche activity: No
Avalanches: none observed, but limited visibility
Weather: Mostly cloudy skies with very light snowfall through 3pm. Moderate winds with strong gusts at ridge top from the northwest. Snow transport was visible across alpine terrain all day.
Snowpack: Storm totals ranged from 4 inches at valley bottom at 9,700′ to 11 inches at treeline. I traveled between 9,700′ and 12,000′ on east and northerly aspects. Below treeline I only found old snow beneath the recent storm on northerly aspects. All northerly slopes below treeline showed soft crusts and facets below the recent storm snow (see photo). Not enough new snow to form an avalanche problem on sheltered, northerly terrain below treeline. No cracking or collapsing.

I traveled on easterly aspects near and just above treeline and commonly found a stout melt/freeze crust directly on the ground with 10″ to 24″ of windblown storm snow resting above (see photo). I was able to produce a few cracks running up to 30 feet in drifted snow but cracks were shallow in just the top few inches of storm snow. Probing revealed a few isolated locations immediately below ridge top that had facet/crust combinations below the recent storm, but in this area, they were only found in old drifts.