Buried well-preserved surface hoar found at Buck Ridge, 10-12mm in size. Photo: GNFAC
Observations and an old natural avalanche from a skier on 01/05.
A skier in Hyalite saw lots of wind-drifted snow on Mt. Blackmore and observed a natural avalanche near the summit. Additionally, they saw several smaller loose snow avalanches during their tour.
Skiers in Maid of the Mist noted multiple nature wind slab avalanches with crowns ranging from 6-12" in size.
Skiers on Hyalite Peak noted a small wind slab avalanche on an easterly aspect.
From obs: "With no slabs, there wasn’t any propagating but with a heavy ski cut two of the point releases were triggered, and the third when skiing. All three went to the ground. All triggered after the first skier made no impact on the slope." Photo: Anonymous
Skiers in Beehive Basin on 01/06 intentionally triggered two small loose-snow avalanches through ski cutting and one unintentionally when skiing downhill. These avalanches started in the new snow as point releases but entrained the weak-faceted snow below.
From obs: "With no slabs, there wasn’t any propagating but with a heavy ski cut two of the point releases were triggered, and the third when skiing. All three went to the ground. All triggered after the first skier made no impact on the slope." Photo: Anonymous
We rode into Buck Ridge toward McAtee Basin, partly cloudy with no snowfall during the day, but 1-2" from yesterday's storm (01/05). The wind was calm in the morning but quickly increased by early afternoon. We dug at First Yellow Mule on a northwest-facing slope at 9400', HS: 74 cm, ECTN 24 on faceted snow 37cm above the ground. In the upper portion of the snowpack was a layer of well-preserved surface hoar covered by snow that fell on the days before Christmas. Near the top of our snowpit, we found another surface hoar layer that was capped by the most recent storm. We continued to the top of Second Yellowmule and dug again on a similar aspect and elevation and had similar test results. (HS:87cm, ECTN 24 45cm above the ground). Both layers of buried surface hoar were present here as well.
In Second Yellowmule, we saw a natural avalanche that was 10-12" on a wind-loaded north-facing slope along with several smaller loose snow avalanches along the same face. On wind-loaded test slopes, we found that recently formed wind drifts were easily triggered. In areas that were missing a wind-slab loose snow avalanches were still sensitive to triggers. These avalanches would start in the new snow but entrain the weak faceted snow below resulting in larger avalanches than what recent storm snow could produce on its own.
In McAtee Basin on another test slope, remotely triggered a test slope, which broke on a layer of buried surface hoar 4-6" deep. Around the corner, we found another recent avalanche, 6-8" deep, that likely broke as we approached it from the top.
The wind blew through the majority of the day and while exiting our previous tracks had been blown over in some areas and active wind loading could be seen.
Photos and Video coming soon!
Rode up the Taylor Fork today. Broken sky at the trailhead, quickly moving to overcast and then snow (S1) by 10-10:30. Sustained strong winds from the S. HS 80-120cm at 9200’, entirely facets capped by varying thicknesses of slab- 2-30cm thick. Widespread large surface hoar in protected areas.
Slabs were touchy, no other signs of instability noted but vis was terrible. Good riding at upper elevations in sheltered zones. Road is a terrifying mix of whumps, rocks and ice.
