Quick report
- Aspect
- Northwest
- Red Flags
- Wind Loading, Poor Snowpack Structure
- Elevation
- 3048 m
- Slope Angle
- 34°
- Red Flags Comment
- <p>The wind deposition that I observed wasn't threatening, but that doesn't mean it couldn't be elsewhere. Obviously the wind has been moving snow around, so it will be important to continue to be vigilant. Of more concern is the 2-cm weak facets on the ground underlying all that beautiful new snow. They are large and I am content to let them be in charge. </p>
Not surprisingly, the facets failed and propagated fractures in ECT test (at 13) and also in a saw propagation test (failure at 15cm).
Hand full of facets from the bottom 20cm of the snowpack.
Snowpack
- Instability Comment
- <p>We dug into a test slope near the boundary creek yurt avalanche from last week. There is a beautiful progressively denser snowpack (from F at the top to pencil at 80cm depth). Unfortunately from 80-100 is a layer of persistent basal facets that you could put in a textbook. This layer failed and propagated at ECT 13 but did not shear (34 degree test slope). The layer is obviously weak, I didn't take any comfort in the fact that the column didn't shear cleanly. The only way to deal with this problem is to stay off of slopes steeper than about 30 degrees, especially large open ones. We were able to ski the slope by paying attention to slope angles and always opting for the conservative line or part of the hill. The next time a significant load is added to the snowpack, I wouldn't even do that. The facets have not bonded significantly at all since being buried, and I would expect them to continue to produce large avalanches for weeks to come, probably for the rest of the winter. I am calling the hazard "considerable", although this is limited to steep slopes facing North. It just doesn't feel right to call it "moderate" with such a poor structure that could easily produce large avalanches still. There is air and ball bearings at the bottom the snowpack. Vigilance is required. Hazard is low on slopes less than 30 degrees steepness.</p>
A little bit of everything, this many days after a storm. Dense settled powder on shady slopes, widespread facets on the surface, increasing melt/freeze crust on S facing slopes, and widespread wind deposition (mostly below ridges)