From Obs: "Observed recent small wind slab avalanches under the ridgeline as well as one larger slide that broke on weak snow near the ground, likely cause by cornice fall."
Forecast link: GNFAC Avalanche Forecast for Tue Jan 10, 2023
From Obs: "Observed recent small wind slab avalanches under the ridgeline as well as one larger slide that broke on weak snow near the ground, likely cause by cornice fall."
From email: "Remote triggered avalanche yesterday on west facing slope of lone mountain backcountry. Observed wind loaded Slope, shooting cracks then woomph, followed by a collapsing snow pack 20 feet ahead. Crown approximately 1.5 feet tall 15-20 feet wide."
A rider-triggered avalanche was reported from a slope near Chimney Rock on the north end of Henderson Mountain. Limited details. Unknown whether anyone was caught or buried.
Rider-triggered avalanche reported near Lulu Pass. Limited details. Unknown if anyone was carried or buried.
From IG 1/7/23: We dug a pit in island park back up Blue Creek on the Centennials side. South facing slope. ECTX
We found a layer of preserved surface hoar that propagated failure in the Taylor Fork. This will be something to watch with incoming snow. Photo: GNFAC
There was 4 inches of new snow in Taylor Fork, and there was wind drifting in several places. We rode to the wilderness boundary to dig a pit. We were on a south aspect at 8,800’. HS 125cm (~4 feet), ECTN5 on surface hoar under the new snow, ECTN21 on facets 1.5 feet below the surface, ECTN 28 on facets near the ground. We rode past the Otter Slide to dig on a north facing aspect, and we had an ECTP5 on buried surface hoar. There was 6” of new snow on top of the surface hoar layer that propagated. While leaving Taylor Fork this afternoon it was beginning to snow. The additional snow in the forecast will likely make this surface hoar layer more reactive now that it is buried. Additionally, the poor structure throughout Taylor Fork could make the deeper weak layers more reactive.
We toured into Beehive Basin for our level 1 class. Widespread surface hoar up to 6 mm on west to south aspects (we did not tour on any other aspects). Buried SH under the recent 7 cm of storm snow was present, though it was not fully preserved. Some feathers were still vertical while others were knocked down. Buried SH was reactive but not propagating long distances. Small, short cracks were observed on that layer in our tour. Wind-loaded pillows from prior loading were visible on much of the steeper western aspects off of the ridge, especially down low and in cross-loaded gullies.
Overall, we were happy with the snowpack structure in our singular pit location, surface hoar not withstanding (see attached profile). Snowpack was right side up and the basal facets were moist, beginning to round, and pencil hard. The ground was warm and soft (and a bit muddy) with a stout 2 cm plus ice layer.
On the lower angle wiggles in the basin, the ski quality was quite good, and the powder was quite loud.