Snow Observations List

Yesterday we tested and skied a well-protected, NE-facing line above Blackmore Lake. There were strong winds during our approach and we observed evidence of wind loading on northern aspects. By around 2 pm, wind speed and wind loading reduced significantly. At our pit location, we observed a thin wind crust (1-2cm) that moved quite readily. This layer did not move during stability tests and did not propagate while skiing, but released readily while skiing. At the bottom layer of the snowpack, we noted that the grain size increased since our visit to the area last weekend, and the faceting in this layer was much more apparent particularly at the bottom of the layer (see photo). 

I am finding very solid snowpack in most areas. We dug one pit yesterday that exhibited two weak layers in the top 35cm and one near the ground. This was a wind loaded slope with HN 230cm. CT test did not fail. No evidence of surface hoar at this location. 9100 feet on a NE aspect.
At lower elevations I found evidence of surface hoar forming, but not necessarily on the snow, see photo.

We are entering a warming trend, which is generally healthy for the snowpack. The conditions are right for surface hoar development; however, I am only finding very isolated evidence of this. Something to keep an eye out for.

We have several weak layers in the snowpack that could fail causing an avalanche, likely a large deadly avalanche. It's hard to find places that exhibit reactive test results, but the evidence is in recently human triggered avalanches. We are not getting a ton of new snow and together with the mild temperatures this will create a strong snowpack over time. The places to watch out for are shallower snowpack areas where the persistent weak layer is easier to trigger.  

From IG 1/7/23: We dug a pit in island park back up Blue Creek on the Centennials side. South facing slope. ECTX

Toured into Hyalite basin and found evidence of what looked like an older and large slide on Hyalite peak. Intense wind scouring appears to have taken place, or the slide ripped to the ground. Ample evidence of wind loading and stripping throughout the bowl left us with enough evidence to turn around without digging. We skied lower angle trees out of the basin and then toured into Divide basin. We dug a pit on the sheltered shoulder of the typical skin track to divide peak and got an ECTx. Snowpack was well bonded and congruent to the ground on this specific E-NE aspect and slope Snowpack was about 100-145cm deep in total.

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. 

Dug a hasty pit on E facing 23 degree slope at 8100 ft above Sportsman Lake. Overall snow depth 165 cm. Found all the familiar suspects including depth hoar, the Thanksgiving weak layer and two 1F layers between 4F layers in the top 60 cm of the snowpack. CT and ECT both produced no results. Temps were warmer in the valley, but didn't show signs of being above freezing above 7500ft.

We skied mellow terrain anyway and made very sporty turns on our nordic skis.

From IG 1/7/23: "Natural slide in avalanche bowl up in fairy lake today."

Location: 45.165, -111.35808 (onX) 

Elevation: ~9,200 feet

While riding a small NNE facing slope near the trail on Buck Ridge, a snowboarder triggered and followed a cornice slide that propagated approximately 75 feet and slid about 20' vertical. The one rider was caught and carried approx. 10' and ended up buried upright, waist deep with no injuries. 

Dug a pit today near the prayer flags and got an ECTX on E slope around 9200’ HS 140cm. Facets near the ground appeared to be rounding and bonding nicely. There is a weak layer at 110cm but not a cohesive slab above it, could be interesting when we get new snow. Did observe newly formed facets on the surface. Minor wind transport at ridge line in the afternoon. Mostly right-side up, quality riding 

More pictures, video and information can be found HERE on our Incidents page.

At 1:30 PM on Jan 6th a large avalanche poured over the cliffs on Saddle Peak, outside the boundaries of Bridger Bowl. Clouds obscured the starting zone. Multiple groups were in the runout zone, including a skier hitting a jump. One person was caught and buried up to his neck. He was able extricate himself and was unharmed. He did a beacon search at the toe of the debris. He estimated the debris was at least six feet deep.

We believe this was a natural avalanche that broke in the new and wind drifted snow. Bridger Bowl measured 6" of new snow with 0.75 inches of Snow Water Equivalent at the Alpine Wx. Station. The avalanche was estimated to be 3 feet deep, and measured on Google Earth to be 550 feet wide and 2100 feet long. 

We rode into The Throne, and skinned up the ridge. While skinning we saw cracks in front of our skis in the 6” of new snow. The wind was gusting from the north most of the day–our skin track was filled in by the time we skied out. Where we dug, HS was 130 cm (~4 feet) on the NE aspect at 8,100 feet. ECTN 8 on the new snow, and ECTN 24 at a layer of graupel about 1 foot down from the surface. This layer was noted by skiers in Texas Meadows yesterday.

While skiing back to our sleds we triggered a small slide in a wind loaded pocket of snow on a ~35º, isolated terrain feature (SS-ASu-R1-D0.5). This was on a southerly aspect, at about 7,000 feet, 4-6” down on surface hoar, 15’ wide, 30’ vertical run.

While skiing around our boundaries I observed well developed surface hoar that was relatively widespread in undisturbed areas. The photo included seemed to go well with the fx. 

I came across this older avalanche yesterday when I was guiding a group in the Kirkwood area, it’s an area in the Cabin Creek drainage. It looked to be an older natural slide probably just after the last storm cycle a few days to almost a week ago now. After seeing the old slide and taking a look we found a safe slope with the same aspect approximately 300 yards away with the same NNE aspect, dug a pit and did an ECT test with stabile results.

Kirkwood

North, North East Aspect

Approximately 39 degree slope (Because of a creek with open water just below the slide, I couldn’t get close enough to accurately measure the slope)

ECTX…When digging the pit we could see what looked like 2 weak layers in the snow pack and a faceted layer at the ground. We had no failures during the test and even after the test when I pulled and pried with a shovel, the snow held together and showed signs of stability.

Recent low density snow was drifted into 10” soft slab from west wind, north of Cooke City. Skier triggered intentional on test slope. 

Same PWL's as observed in recent past. Newly forming wind slabs and a more recently formed 2 cm (very fragile) melt freeze crust at 228 cm. 

4-5 in. HST on top of melt freeze crust

A lot of blowing and lightly falling snow the past few days. Larger drifts forming on the NE aspect ridge line where we dug our test pit today.

CTH 192 cm above melt freeze crust

Submitted via instagram: "Ectp12 and 22 at 85 and ~25-30 cm (less planar) respectively on S aspect we did not ski and bailed from after initial pit ~300m away in slightly more protected terrain yielded ectN. Was dug adjacent to ~33-35 degree slope. Slope is located near the head of Flanders Basin"

Dug a quick test pit yesterday (2022-01-04) in Texas Meadows zone on a SW asp at 7800 ft. 

Had an ECTN21 down 25 on a thin layer of small (size 0.5-1) facets. Though it didn't propagate, the block sheared off easily and cleanly on this layer after the test.

Also got an ECTN26 down 17 on a layer of graupel ~1cm thick which overlay a melt-freeze crust ~1cm thick. The graupel was large, up to size 5.

We additionally noticed some surface hoar up to size 4 in isolated shady places, though much of it appeared to have been knocked flat from previous wind.

Extended column test at lat/long 45.84006, -110.93326, elevation 7698 feet, east facing, approximately 20 degree slope.  Depth of snow = 95 cm.  There were 2 obvious interfaces: 1) approximately 20 cm below the surface (ice crust) and 2) approximately 20 cm above gound, the heigth of the faceted snow.  ECTP18, shear quality q1.  The snow is noticeably dense/stiff.  We stayed on lower angle slopes, the skiing was good.

We rode into Teepee Basin first. We had perfect visibility and saw no avalanches. We dug on the far north ridge on a south facing slope: HS 105, ECTN25 on facets about 40 cm off the ground. There is a lack of recent ava activity and ECTN score, which point towards a snowpack trending towards stability, but the snowpack structure is still suspect: facets underlying a slab.  

Next we rode to a small and recent avalanche in Cabin Creek. We were alerted to it last night. Although it was steep and wind-loaded, it illustrated the lurking problem we are finding in most areas. Faceted snow is not entirely trusted. We did not see evidence of avalanches on Skyline ridge and folks are starting to climb.

Extremely crusty snow. Dug a pit and found three very defined ice layers around 5500ft.