Quick report
- Red Flags
- Wind Loading, Cracking, Collapsing
- Red Flags Comment
- <p>We got several collapses today. These were on upper elevation northerly slopes where the old snow surface had remained dry and soft, with some weakening due to faceting. Recent winds had created a 10-15 cm hard wind slab on top of this weak snow, with new storm snow and wind-blown snow on top. The collapses were likely from the weaker snow underneath these recent wind-loading events.</p> <p>Also quite a bit of cracking in new storm snow, especially in areas that were wind drifted.</p>
Overall stable conditions, but pockets of wind drifted snow above 9000' remains the biggest avalanche concern for Friday. I was able to ski cut some steeper, northerly slopes at the upper elevations, and couldn't get any sluffs to move, but I wouldn't be surprised to hear others were able to get sluffing in the storm snow.
Video describing structure where we were finding collapsing.
Snowpack
- Instability Comment
- <p>Southerly winds were creating shallow pockets of fresh, sensitive wind drifts in the mid and upper elevations, generally above 9000'. Most of these drifts were shallow (< 10 cms), but some were up to 45 cms thick. The widest wind slab I could get to propagate was 15'. With continued snow and winds in the forecast, this should remain an issue for Friday. </p>
10-15 cms new storm snow, with some dense drifts that were sensitive. Storm snow is quite damp below 8500'. The snow came in warm enough that it has bonded well to the old surfaces, even in upper elevations where the existing snow surface was dry.