Recent Avalanches? | No |
Collapsing (Whumphing)? | Yes |
Cracking (Shooting cracks)? | No |
Decided to skin peak three and do a snowpack evaluation after work. Most of the mountain was socked in for the afternoon/evening and visibility was very poor. Made for great snowpit digging weather! Toured up the usual skintrack and stopped at ~2800′ to dig a pit and check the snowpack. Some whumping observed on the way up. Rode back down after the snowpack evaluation due to poor visibility and limited daylight.
Recent Avalanches? | No |
Collapsing (Whumphing)? | Yes |
Cracking (Shooting cracks)? | No |
Some minor whumping observed on the tour up.
~25F at the trailhead with cloudy conditions. Very limited/poor visibility once above the treeline. Clouds cleared for ~1 minute around 5:15pm giving myself and everyone else on the mountain a glimpse of the sunset.
New settled snow at the trailhead from the weekend storm. snow thinned out as I toured up and surface was crusty for the rest of the skin up.
Periodically checked snowpack with poles while touring and did not observe an obvious weak layer.
Stopped at ~2800' on a representative slope just north of the skin track to dig a pit.
Pit details: 2800' elevation, SW facing aspect, slope angle = 34 degree. Pit was 150cm x 60cm x 135cm. Hit ground at ~135cm depth. NOTE: While digging pit - ground collapsed under me once I reached ~80cm depth causing me to sink ~25cm. This indicated a weak layer that I confirmed with my hand hardness test.
Hand hardness Test: Snowpack appeared to be right side up for the first ~80cm. increasing hardness from fist to single finger UNTIL about 80cm depth. As suspected - weak layer found right at 80cm that caused my hand to penetrate the snowpack up to my wrist. Snow was easy to compress with my fist to the ground. I assume this is the weak Thanksgiving/early Christmas crust.
Shovel Shear test: 30cm x 30cm column isolated. Entire column collapsed as I pried with minimal force. Collapse occurred at weak layer around 80cm depth. Seeing this - combined with the hand hardness test made me start to think the avalanche danger may have been higher than initially assumed.
CT: 30cm x 30cm column isolated. CT27 Q2. Was surprised that compression test did not yield results until 27. I started feeling a bit better about my ride down after seeing this
ECT: 30cm x 90cm column isolated. ECT30X. The extended column test was even more surprising as the column did not collapse at all. It took a "WWE style" elbow drop for me to get the column to collapse. When it did give, the top slab slid right above the weak layer. Stability seemed MUCH better than initially assumed.
I would have liked to dig a second pit to confirm the snowpack stability, but unfortunately ran out of daylight. Based on these tests the snowpack appears to be stable, but I would still be concerned about the persisting weak layer near the ground.