Quick report
- Aspect
- North
- Red Flags
- Wind Loading, Poor Snowpack Structure
- Elevation
- 3231 m
- Slope Angle
- 27°
- Red Flags Comment
- <p>We don't have the cracking and collapsing we were seeing a couple weeks ago, but we do have the same persistent weak layer as well as wind loading of our soft surface snow.</p>
Video illustrates the moderate winds that are buffeting the southwest mountains today and rehashes a lot of the details written in this observation. NOTE - the extended column test (ECT) I reference in this video turned out to be an invalid test because (as I discovered after recording the video) the block was not completely isolated during the test. It's a bummer because it would have been valuable to see if the fracture we got in our compression test would have propagated across our extended column.
The faceted snow that our column in the compression test failed on.
Our persistent weak layer plainly visible in this photo.
Snowpack
- Instability Comment
- <p>Even though the cracking and collapsing of recent past weren't an issue on my tour today, the persistent weak layer (PWL) is still very much in play as evidenced by an energetic planar fracture in my compression test. In some ways the danger is decreasing because the PWL is harder to trigger and in others the danger is increasing because wind loading and significant new snow in the forecast will stress this weak layer. This problem seems more relevant on polar aspects, as the warm weather at the end of January created a notable suncrust on solar aspects that should make the PWL harder to trigger in those places.</p> <p>Strong gusty winds are clearly loading leeward aspects and I expect to see avalanches in the wind drifted snow.</p>
North and east aspects are getting loaded, south and west aspects are getting scoured down to a sun crust.