22-23

We toured and skied on the Throne today.  Ended up being a one and done as the snow depth there still isn't deep enough to cover hazards, we hit a lot of rocks.  This was our second attempt here, tried on Nov 17th and thought there would be enough snow by now but it seems strong winds have been stripping this area of snow as compared to Bridge Bowl for example.  Snow depth on the east aspects of the Throne was highly variable but most of the coverage was on the order of 12"-16" deep.  East aspects varied from breakable wind crust to some supportable snow/crust with F hardness wind affected snow on top.  The winds must have been pretty consistent, even the tree protected north facing lower elevations of the Throne were wind affected. The entire southern aspect of Naya Nuki also looked very wind stripped with large bare spot visible at mid elevation.  The upper elevation east facing aspects above the Throne were also very wind affected.  We dug a pit about 75' below the high point of the Throne and then skied the north facing gully back to the North Fork Brackett Creek drainage.  Included a map pic to show were the pit was located.

ECT Results

12/8/2022 11:50am

HS: 80cm (this area was wind loaded, 200' away in the gully the snow was 30-60cm deep)

Air temp: 20F  Sky Cover: Clear  Precip: NO  Wind: Calm

Elevation: 8300       Location: N 45deg 52.9547min  W 110deg 57.1631min

Heading: 330

Slope Angle: 30deg

0-25cm - 1F, some faceting at this interface

25-65 - 4F, faceting at a snow interface layer at 55cm (possibly a decomposing suncrust?)

65-80 - F, wind deposited snow, not much cohesion

ECTN 21 at the 55cm layer, very rough failure plane, no propagation

ECTX on the remainder of the column

Comments:  The area is so variably covered right now that this test was mostly for curiosity sake and gave us confidence to ski the north gully (lots of sharky rocks) and call it a day.

Two small natural avalanches observed today from the YC. Both on likely wind loaded easterly aspects on slopes around Cedar Mountain at roughly 8,000’. 

We rode to Daisy Pass to look at the avalanche that was triggered by a snowmobiler two days ago (12/6/22). It was on the slope east of the pass that people often climb up and out, steeper than the normal route out. It broke 2-3 feet deep and 250-300’ wide, R2-D2. At the crown it broke on a weak layer about 100cm above the ground, but it broke closer to the ground in many places lower on the slope where the snowpack was shallower and weaker. I would guess one of those areas is where it was triggered from.

Next, we rode around the back of Fisher Peak to Lulu and dug on the southwest slope below the weather station. Here it was shallow, 100cm. There were weak facets near the surface, but no slab on top of them, maybe due to the southerly winds scouring it. Could become unstable if loaded from the north or with a lot of new snow. Finally, we rode up to the shoulder of Scotch Bonnet and dug on far south Rastas. HS was 145cm, we had ECTP22 and ECPT27 on a thin layer of facets sandwiched between two crusts 55cm off the ground. Despite the hard force, these collapsed dramatically and re-iterated the possibility of triggering a large, high-consequence avalanche.

Crown of avalanche that was triggered 12/6/22. AMu-R2-D2-O

Looking down path of avalanche triggered by a snowmobiler on 12/6/22 near Daisy Pass, Cooke City. NW-N aspect, 9,800'. Photo: GNFAC

Crown of avalanche triggered by a snowmobiler on 12/6/22 near Daisy Pass, Cooke City. NW-N aspect, 9,800'. Photo: GNFAC

Avalanche triggered by a snowmobiler on 12/6/22 near Daisy Pass, Cooke City. NW-N aspect, 9,800'. Photo: GNFAC