Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Enji Cooper
Observation Date:
November 20, 2022
Submitted:
November 20, 2022
Zone or Region:
Stevens Pass
Activity:
XC Skiing/Snowshoeing
Location:
Rock Mountain via Rock Mountain Trail

Triggered Avalanches

Did you trigger any avalanches? 
Yes
Was it intentional? 
No
Avalanche Type:
Wet Loose
Size:
Size 1: Relatively harmless to people
Elevation:
6.4k'
Aspect:
E
Comments:
Broke some superficial hard slabs (likely wind slabs). The slabs were small (<1/2"), but were present on all eastern aspects.

Signs of Unstable Snow

Did you see shooting cracks? 
Yes, Isolated
Did you experience collapsing or whumpfing? 
No

Observations

Snowpack depth and characteristics were a bit all over the map today.
Below 4.8k', the snowpack was almost non-existent, and was only present in shaded areas. Above 4.8k', it was a mix of conditions:
- Large surface hoar crystals were present in some areas between 4.8k' and 5.4k'.
- In leeward areas, there was a fair bit of dry wind fetch. Boot penetration here was at least 1.5' off the beaten track.
- South facing slopes had refreeze crust above treeline and snowpack was extremely shallow along the ridge (<1'). - East and north facing slopes had wind effect (satsurugi). It looked like the prevailing direction of the wind was from the west, but there was some deep snow on the ridge (1'~2'), but the majority of the snow seemed to be supportive when using snowshoes. Cornices hadn't formed visibly yet, but I didn't closely inspect the east ridge. - Much of the surrounding mountains (Howard, Nason Ridge) were bare of snow on steeper aspects; much of the snow seemed to be in the basin between Rock and Howard.

Media

Howard in background: left of center.
Looking east at basin above Rock Lake; high point between Rock and Howard to the left
Wind effect on northern side of ridge east of Rock Mt south peak. Chiwaukums in background with Stuart (left). Arrowhead (center). Daniel and Hinman in the background and Jim Hill in the foreground (right).
Surface hoar
Rock Mountain summit to right; Sloan Peak and mountain loop highway peaks visible to left in background.
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