Northwest Avalanche Center - Public Observation

Name:

Enji Cooper

Observation Date:

February 4, 2023

Submitted:

February 5, 2023

Zone or Region:

West Central

Activity:

XC Skiing/Snowshoeing

Location:

Cleveland Mountain

Comments:

Was easily triggering wet loose avalanches (rollerballs and pinwheels) along steep north-facing aspects that entrained additional snow and grew in size. I would classify this area as "near treeline".

Did you observe any avalanches?

Yes

Comments:

Saw a large number of mostly D1 wet loose avalanches around the lower basin.

Our group picked Cleveland Mountain because some other groups had made it up the prior weekend and had made a snowshoe/boot track.
Snow well-below treeline was punchy/consolidated. Areas where more precipitation fell off of trees resulted in more stable snowpack.
Once we started gaining the ridge though and got into more consequential terrain near treeline, the snow grew deeper and more unstable. We followed others' tracks over the knife edge ridge, which was the least exposed/"best" route to the lower basin, and I started observing a lot more surface instability on the freshly fallen storm snow. Like described in yesterday's West Central forecast, the storm snow was poorly adhering to the base layer--which was pretty consolidated, e.g., 4F+ / pencil hard. Our group cautiously entered avalanche terrain one at a time and almost turned around at one section due to instabilities we saw and consequential terrain.
Interestingly though, the snow became more stable above treeline (4.7k'+) -- I suspect because the temperatures were just cool enough that the surface snow was less reactive. We stuck to the north/northwest ridgeline though which didn't have any remote triggers nearby, had lower angled terrain, and lower coverage snowpack.
On the way down we took the northeast ridge, which was less exposed to avalanche terrain (in key areas), and had less consequential terrain/holes between boulders.
Going back over the knife edge ridge, on the north side I triggered the top-layer of storm snow with my snowshoe, which entrained additional snow (in pinwheel form) and grew to beachball size.
I absolutely, 100% would _not_ have wanted to ride skis or a board yesterday, and only felt marginally secure in snowshoes.
Yesterday was cloudy with rain below 4k', light snow (S-1) near treeline, and no snow above treeline. The south wind on the summit was calm (5-10mph). Temperatures felt like they were in the low to mid 30s.