At the base of G2 I triggered a 3 inch x 100 foot soft slab. I was surprised how far it propagated. It looked like it failed on a density change under the morning's new snow. 40 feet up on the first large bench we triggered another slide, 6 inches deep, the entire width of the bench. It could have pushed a climber off if they were in the middle of it. It was snowing steady (1"/hr) and wind was minimal, but a few hours later we could see plumes higher up in the gullies.
It had such zip to the propagation that I'm thinking it might take a day for it to not be reactive. There was no way we wanted to get on anything open and steep.
Dug on a NE aspect at about 7800’ on Mt. Ellis. Noticed pretty significant wind loading/cornice development from yesterday and was easily able to get small cornices to break off. Most notable test result was ECTP16 down 35 cm on a layer of surface hoar. Besides the concerning surface hoar layer the snowpack was generally right side up and seemed pretty solid. Photo of pit profile attached.
The wind had hammered snow surfaces at all elevations above tree line on Mount Blackmore. There was evidence of several R1-2/ D1-2 wind slab avalanches that likely ran this weekend on the east face of Blackmore.
Three to four inches of new snow from yesterday sat on top of the dust layer that got deposited across most of the forecast area on Monday and Tuesday. Photo: GNFAC
We toured up the standard ascent route on Mount Blackmore to the shoulder. Three to four inches of new snow from yesterday sat on top of the dust layer that got deposited across most of the forecast area on Monday and Tuesday.
We stopped and dug a full pit on the lowest pitch of skiing and found good stability in this wind-sheltered terrain. Incidentally, this lowest pitch was also the best skiing by a large margin. All the terrain above this was very wind-affected. We were looking for near-surface facets and surface hoar that formed last week and got buried by recent snow in some areas. We didn't find it. This bodes well for long-term stability, but we'll keep looking. Test scores were unremarkable, ECTN5 below yesterday's snow, ECTN15, 17, and 30 at various levels within last weekend's storm snow. No other failures, no propagation.
The wind had hammered snow surfaces at all elevations above this. Surfaces stiffened. There was a tree that blew over recently. Elephant Mountain and the summer trail area were scoured down to the tundra. There was evidence of several R1-2/ D1-2 wind slab avalanches that likely ran this weekend on the east face of Blackmore.
We dug again on the shoulder with unremarkable results and no evidence of new weak layers that will be players.
Bottom Line:
Wind effect is widespread.
It is difficult to tell precisely where loading occurred with the fresh snow covering drifts. You won't know until you move into the terrain and feel the underlying snow stiffen under your skis, board, or sled (I don't like not knowing).
We didn't find any evidence of new weak layers of concern.
Manage it by:
Maintaining a conservative mindset in all upper-elevation terrain that isn't obviously scoured.
If you want to ski and ride in steeper terrain (slopes above 30 degrees), do so at lower elevations on slopes sheltered from the wind. We didn't find new weak layers below this weekend's snow, but I would still dig 2-3 feet down to look for them before committing to avalanche terrain.
