Snow Observations List

From FB: We saw a fresh break on the west face of sage peak last night, I would guess around 9500’.

We rode north of Round Lake this morning (2/6/23). Near Long lake we measured 9" of new snow = 0.55" snow water equivalent. Near the Goose Lake wilderness boundary we measured 10" new snow = 0.65" SWE. In places there were 1mm facets below the new snow.

Wind was moderate-strong at the ridgelines, but calm around the lakes. 

There was a small snowmobiler triggered slide on a convex bench between Sheep Mtn. and Round Lake that was triggered this afternoon. It was 1.5-2' deep, 30' wide, and looked to have broke on a weak layer below last week's snow, on a freshly wind-loaded slope. In a relatively shallow, rocky area (photo attached).

We rode up Yale Creek to across from Arange Peak, then back into Yale Creek. We dug 3 snowpits looking for weak layers and found them a foot or two under the surface. Feathery surface hoar mixed with small, sugary facets were found in all. This layer was not propagating in our tests, but we know that nearby in Lionhead they avalanched. We are not completely trusting of these layers, especially at higher elevations where wind drifts would be adding even more weight to these layers.

This afternoon (2/5/23), we rode over Daisy Pass in hopes of seeing the recent skier triggered slide on Fisher Mountain, but it had started snowing and visibility was too limited to see the crown or get to the slide. We rode around the back of Fisher to Lulu Pass and then up to the south shoulder of Scotch Bonnet to dig a pit. There was an old, large pile of debris at the bottom of one of the Rasta Chutes that I assume slid last weekend.

We dug a pit at 9,600' on a southwest facing slope. HS was 160cm. Below last weekend's snow (1 foot/30cm deep) was a 10 cm thick layer of soft facets (F+ hardness). We had an ECTN 21 and ECTP 21 on this layer. The recent skier triggered avalanche on Fisher probably broke on this layer, on a more wind-loaded slope. This layer will be a problem for a while, especially as it gets loaded by more new and wind-drifted snow.

Wind was moderate out of the southwest-west, and at 4pm there was 3" of low-density new snow.

ECTPX in two pits at the top of Texas Meadows. No active wind loading. 

We observed some crowns from recent slides just south of the Flanders Peak east glade while touring up Flanders today. The snow was wind affected and slabby especially towards the ridges. No other signs of instability observed. We opted to stay in the trees and minimize exposure on the ski descent.

Heading up the Genesis gully towards Zack Attack on 2/5, we turned around after finding multiple very reactive slabs. The first slab broke very easily, ~4 hits from the wrist, and had a very clean shear ~4in deep. The second slab was more difficult to trigger and did not have a clean shear, but was maybe ~1.5-2ft deep.

Me and a buddy were out skiing/camping in the Hyalite Lake area. Late Saturday afternoon we started skinning up towards Hyalite Peak. The path up to the ridge was super hardpacked and windswept. We got up and there was quite a bit of snow loaded above the north slope. I dropped over the side and took about two turns before the entire face above me released from the very top and traveled down the entire north side down to the bowl below. I was able to get to the rocks on the side and my partner was able to pick his way down. The crown looked a few feet deep from what I could see and stretched across the entire top of the line.

We toured up the ridge between Going Home Chute and Tyler's (below prayer flags). We saw evidence of a large avalanche that broke during the avalanche warning last weekend in Going Home Chute, R3-D2.5 (see photos). It appeared to have run to the end of the runout zone and tipped over small trees. We dug a pit near the top of our ascent on a west aspect at 9,100'. HS was 160cm and we found surface hoar buried 55cm deep (105cm above ground). It did not propagate or easily break in our tests, but it was a clear stripe in the wall and may have contributed to the adjacent large avalanche last weekend.

We dug a second pit over the ridge in Middle Basin on an east aspect at 9,200'. HS was 175cm and buried surface hoar was 80 cm deep (95cm above ground). It did not break or propagate in standard ECT, but did propagate cleanly after 4-5 extra hard hits. Old faceted layers deeper in the snowpack were generally strong in both pits.

We also saw a crown of a large avalanche from earlier in the week on the west side of Beehive Basin, on an east facing slope around 8,800'. R3-D2, 2-3 feet deep, 150' wide.

Skied Mt Ellis today. The burn was heavily wind loaded at the very top but softened significantly as you got lower on the slope. I got an ECTX in my pit, the snowpack seems to be adjusting well to the recent load in this area. There were still multiple layers of concern that would give me pause to step out into bigger terrain throughout the advisory area. 

Toured/ skied on S though E aspects between 6000' and 8200' and observed the following:

-No slab avalanches observed

-Several localized whumphs 

-Two hand shears that failed upon isolation down 35cm, sudden planar failure (storm snow/ old snow interface)

-Two hand shears that failed easy down 35cm, sudden planar (storm snow/ old snow interface)

-Stomped one freshly wind-loaded rollover on micro-terrain and released a small (15 cm - 30cm thick) windslab

Dug a quick pit on an E aspect at 8200' and observed the following:

-HS 120 cm

-ski penetration 22cm

-boot penetration 53cm

-CT 17 resistant planar down 35 cm (storm snow/ old snow interface)

-ECTP 14 down 35 cm (storm snow/ old snow interface)

Steady, moderate winds all day from SW and W; no blowing or drifting snow observed in our immediate vicinity

From FB message: I triggered this one Thursday night (2/2/23). Got lucky it didn't gain speed and sack on itself. Been in this zone 1000 times, never seen it slide, always gotta be on your game... NE aspect in Beaver Creek.

Our group toured up into Beehive Basin yesterday with the goal of skiing Peru and returning via Middle Basin. Our ascents and descents on the day showed signs of small pockets of wind slab instability (cracking and small pockets pulling loose), but nothing significant. On our final ascent up the backside of middle peak, there was a large shooting crack, maybe 30 feet in length, but we adapted our ascent route and were able to avoid further significant instabilities. Hand pits showed a thin 2" wind slab on our final ascent slope. Throughout the day we noticed a few old crown lines varying from 1 to 2' in depth and up to about 150' wide. These crown lines were on E, NE, NW and W aspects. The debris appeared to not be recent as it was covered with new snow and eroded, and some of the crown lines were filling in. 

A 2’ storm snow avalanche in the Chippewa Notch area was apparently triggered by a rider. It propagated significantly across complex terrain, and ran through plenty of terrain traps/trauma trees.

We looked at the snowpack at lower elevations in the northern Gallatin Range (SE aspect, 8,300' elev.) and found a layer of buried surface hoar below last week's snow that was reactive in stability tests (ECTP20, ECTP22). There was also weak, sugary snow through the bottom half of the snowpack that should be kept in mind, especially where the snowpack is relatively shallow. Triggered one small, isolated collapse on a west facing slope around 7,500' where the snowpack was mostly 1-2' deep weak facets, and we found one small pocket that had a drift over the weak snow. The buried surface hoar below last week's snow makes large avalanche possible to trigger for at least a few days.

Impressive avalanche cycle in the Bridgers to view as the skies clear.  Most slides seemed to have happened mid storm.  Here’s some photos of a large slide on the west side/behind north boundary.  Not sure the name.

Avalanche (possibly sled/human triggered) on an easy to northeast facing slope around 9300 feet.  There were lots of sled tracks on the slope, which is located just out of the wilderness at the far end of Buck Ridge.  Slide and sled tracks appeared to be from after the weekend storm and we're covered with light snow from the last couple days.  Noted lots of wind transported snow along buck ridge this afternoon.

Today we skied the northmost avalanche path on the east face of Blackmore; the farthest lookers right avi path before the trees. There were strong winds blowing from the southwest which created a very strong, 3-5in deep, wind crust. Certain aspects were heavily wind-loaded creating a very pocketed snowpack in some places. In the first 100 feet of my descent, I experienced three whumpfs; all of which came from different pockets of snow. Some areas appeared to be very well bonded, whereas others were far less so. We also observed multiple crowns across the eastern face, all of which appeared to have slid a few days ago. They ranged in width from 50-300ft and looked to be 1-3ft tall. The runout and debris were not visible. 

Dug at South facing snowpit at 9700' near the base of a wind-loaded slope, ECTX HS:280. Continued on less than 200' up the slope, the skier breaking trail triggered the avalanche. The third skier in the group of five was caught, carried, and buried to the waist. The crown was 1-2' deep, and 50 feet wide. Location: South of Fisher Mountain. Yesterday triggered a small windslab on a north-facing slope on miller ridge, no one was involved. 

We triggered this very small slide on a steep convex  rollover by mt abundance. South facing. Triggered from on top by snow bike. Was only 60’ wide and didn’t run far at all. About a foot deep.  Some impressive high mark tracks in the area. No other signs of instability today.