Observation Date: 11/30/2019
Pyramid Peak – Southern Swans
Low teens on arrival (11am) and departure (5pm). Very light wind, except above 7600′ on the SW ridge to summit (it was blowing just enough for minor snow transport of the very low density fresh snow). Generally clearing skies through the day, with VERY light dendritic snow showers at times with passing clouds.
New Snow: 3-6″
One very subtle collapse ~7400′ west aspect. No other red flags. No confirmed recent avalanche activity, although there appeared to be possible D1.5 crowns off Devine Peak north ridge (ESE aspect) from the high wind event earlier in the week.
Unlike the Bitterroots, which seem unscathed from the high wind event earlier this week, the Southern Swans exhibited obvious signs of being affected by the high wind event: near surface wind slab (below the fresh snow from yesterday), sastrugi, and exposed old crusts (that were only covered with a dusting of very recent snow).
No base below 6000’ (only ~2” fresh snow over ground). Between 6000-7000’ base is patchy, and really only exists in wind loaded catchment areas. Above 7000’ there is a decent base (primarily comprised of melt-freeze crusts, with faceted layers between, and up to 6” recent snow at surface).
Stability tests in two locations yielded very concerning results due to extensive faceting on top of a mid-snowpack melt-freeze crust (likely formed 11/17-18). See the photos for further info.
Observer: Mat Brunton