Quick report
- Collapsing
- specific
One of the biggest takeaways from our field observations was the degree of spatial variability. On a North aspect (5,300') we found just over 2' of storm snow from Feb. on top of the Jan. facets. Moving to an east aspect at the same elevation (one drainage over) we found the 1/31 Buried surface hoar layer, resting above the Jan facets. This leads to greater uncertainty, and the only answer to this uncertainty is increasing our margins and sticking to simple terrain. The bottom line is we don't like the facets or buried surface hoar in our pits.
After conducting two snowpack tests my partner walked above our snowpit on his skis and jumped once, about 3' from the pit. The entire slope collapsed, it was audible and visual. There was a very large 1/31 Buried Surface hoar layer on top of the Jan. facets that was the culprit.Weather
- Air Temp
- 17
- Cloud Cover
- obscured
- Wind Loading
- moderate
- Recent Snowfall
- 14
- Snow Avail For Transport
- large amounts
Moderate winds were consistent in the afternoon from the SW. The wind was removing snow on the frontside of the ski area, or compacting it into a slab. Temperatures were colder than expected, and on our exit, we skied into freezing fog. Close to 6" of new snow was observed in protected locations.
Snowpack
Poor snowpack structure was the takeaway in the two snowpits we dug. Our first pit on a North aspect revealed full propagation in an Extended Column Test in the Feb. storm snow down 45 cm. There were no failures on the Jan facets, but there also wasn't a slab found above the known weak layer.
Our second pit (same elevation 5,300') revealed the 1/31 Buried Surface Hoar layer very intact and large (20mm). There was no second-guessing the presence of the surface hoar once we excavated the snow pit. This was some of the largest buried surface hoar I can recall seeing. Again there wasn't a slab in the Feb storm snow (65cm), but we did have full propagation ECTP25 down 65cm on two tests.
With the snowpack collapse we received after our two ECT tests, I feel confident in saying if we were on a slope greater than 30 degrees the slope would have released.