Northwest Avalanche Center - Public Observation

Name:

Enji Cooper

Observation Date:

December 4, 2022

Submitted:

December 4, 2022

Zone or Region:

West North

Activity:

XC Skiing/Snowshoeing

Location:

Excelsior Peak via Excelsior Pass Trail

Did you observe any avalanches?

Yes

Comments:

Observed multiple small wet avalanche debris piles which appeared to be triggered by recent tree bombs. All were reasonably small, but one had some fan-out.
All of the debris piles were on south facing aspects.

None reported

Observed a variety of snowpack conditions throughout the day.
Below treeline up to 3.8k', the snow was consolidating, but sloppy in the afternoon (slush puppies :)..).
Above 3.8k', the snow got much deeper (1'~3') and was really unconsolidated out in the open.
Above 4.8k', the snow drifts were 3'+ deep above the trail bed. It was close to crème brûlée consistency on the beaten track: hard on top, but once you broke the surface, it was gooey powder all the way down. I postholed a few times up to my crotch, and apparently others booting the track were postholing a foot or two as well. Bootpen was at least a couple inches on the beaten snowshoe/old skin track.
The depth I measured out in the open, closer to near treeline, was 150-155cm (HS). Qualitative observations were large surface hoar on top, weakish (but bonding) storm snow beneath it of varying strengths. There were multiple micro-interfaces in the storm snow which made for diffuse slab breaks. I also observed the 2 sugar snow/pencil-hard-ish (depending on where you touched it) faceting crusts mentioned in Sunday's forecast, around 75cm and 80cm HS. The crusts were easy to identify with my crystal card and avalanche probe.
Most of the snow encountered above treeline was either completely unconsolidated to a point, but also incredibly unreactive on south facing slopes. Multiple individuals went up from the pass south of Excelsior to the peak (booting, snowshoeing, and riding skis/snowboards) and there weren't any visible avalanche concerns. Some snowmobiles were nearby as well (presumably outside the wilderness boundary).
Wind effects were visible on some south facing aspects to the west of Excelsior Peak (closer to Excelsior Pass). I suspected wind loading on north facing aspects, but didn't actively seek out it out, since it was along the ridge line. I also didn't want to push my luck and go across a SW/W facing slope in the afternoon, given that there was some slightly buried wet loose debris nearby.
I tried to do an ICT in addition to a relative pressure test, but unfortunately the snowpack was bonding too well and breaking off in diffuse slabs, so I couldn't dig a column without it partially collapsing.