Snow Observations List

Saw a group of skiers trigger a small wind slab avalanche on an eastern aspect at around 8,300' in the main fork of Hyalite in "Candy Land" just south of the climb Big League Chew at 2:00pm on Saturday (11/26). Crown looked to be around 2" to 1' and 90' wide. The slide ran maybe 100'. No skiers were caught. It was triggered as the first skier traversed out onto the intended ski line from the trees which they skinned up. The fracture extended from the tips of the first skiers skis and ran across the slope and underneath a small cliff band. The group skied out on a slightly lower angle slope adjacent to the slide. My group watched from below an adjacent ski run approximately 300 yards away as the slide happened. We had dug a pit on a similar aspect in the area approximately 30 minutes before the slide and found 85cm of snow with a weak layer at 42-45cm which failed CTs but we couldn't get propagation. (CT22, ECTN21). It looked like this was probably the layer that failed in this slide.

Skied bacon rind skillet & one gulley just south of it today

No avalanche activity, cracking or whumphing 

No wind today up to 9000’; no evidence of recent wind-drifted snow

No new snow; Snowed s-1 all morning with no real accumulation (trace)

Average HS 60 cm at Skillet ridge top (approximately 9000’); 70 cm max depth 

Faceted surface snow on cold aspects (skied well) and 3 cm thick crust on anything remotely solar

Dug one quick pit on E aspect at 8840’:

HS 60 cm

CT 13 Q3 down 17cm

CT 23 Q3 down 25 cm

ECTN 24 down 30 cm

Yesterday toured up Bacon rind on the spur just to the south of the Skillet, dropped west towards Ernie Miller ridge and skied two laps on the N end of the ridge. We travelled back to the car on the same route and skied out the skillet.

60-70cm HS observed on E aspect at the top of Bacon rind Ridge 

No Cracking or Collapsing observed all day 

Great supportable skiing, didn't fall through to facets anywhere 

pole probes felt uniform/generally right side up all day

1F zipper crust on the surface of anything solar

ECT Test Results

Location: 300ft below Lionhead Peak

Elevation: 9250ft

Aspect: East, 88deg

Slope Angle: 33°

Total Snow Depth: 115cm

Result: ECT 22, at 15cm deep (new snow interface).  At this location the top 10cm of new snow was loose, then 5cm of new snow formed into wind slab.  Remaining 100cm of snow ECTX, well consolidated, no visible layers, approx 2F hardness to the ground.  

Comments: Failure at the new snow interface seemed very spatially dependent.  We had an ECT 11 in another area. 

Skied multiple locations along Lionhead Ridge over 3 days, NE to E aspects.  Our observations were in line with the avalanche reports.  New snow was generally 15cm deep and weakly bonded to the existing snowpack.  There was minimal wind transport during this time along the more protected NE aspects along the ridge line, so the snow was not particularly wind loaded or consolidated.  Even so, there was multiple instances of small natural loose snow avalanches on steeper aspects or terrain rollovers.

Toured to the ramp and Bradley's Meadow on 11/25 around noon. Temperature was 45 F and wind was calm. Snow surface was moist 5-10cm deep on most slopes. The snow surface on shady slopes above about 8,000' remained dry, despite temperatures above freezing at all elevations.

I dug one pit at the top of Bradley's Meadow where it is moderately wind-loaded on the south end, east aspect at 7,800', and one pit halfway up the Ramp on northeast aspect at 8,200'. Both were just over 2 feet deep. I had ECTNs below the recent storm/wind-drifted snow, on a layer of small (0.5-1mm) faceted crystals. Lower half of snowpack had layers of 1-2mm facets, but supportable and generally stable for now. 

Skied out to the head of beehive basin for a fitness / recon tour. Made it about halfway up the head wall to the pass between Beehive and the Mirror lake basin. At lower aspects boot top powder with surface hoar predominated with patches of breakable sun crust. Higher in the basin (2800-2900m) south facing aspects were thin, windblown, and sun effected. Ski conditions were completely breakable sun crust by apx 5pm. Lots of moving snow on south facing aspects. I did not dig a pit. See attached photos. In the panorama, most of the chutes to the right of the arrow (4th of July couloir) had slid, it looked like it was mostly limited releases from sun warmed rocks. I did not see any natural slides to the left of the arrow. 

Surface boar forming in sunny spots at lower elevations

Pin wheels coming down on south facing road cuts

Backside skiing was already getting heavy just after 10, reasonably heavily trafficked since last storm, someone ski cut just below cornice with no movement.

Front side has a supportable sun crust under the last 4" storm

Well developed surface hoar was widespread this morning near Cooke City. The strong sun burned it off on aspects that received sun, but it was preserved in shaded areas. Strong south winds picked up in the afternoon in the Sheep creek drainage. We dug two pits (ectx both times) and a shovel shear test just below sunset peak, and found stable snow. 

Just wanted to share a few photos and videos of how windy it was up at Bridger today. The strongest winds/gusts were mostly mid-mountain and were blowing from the North-Northwest. Lots of snow moving around and stripping of snow surfaces as the videos show. 

Hey guys, wanted to share about a small avalanche I set off today. Snow was getting warm on my way up 4th of July couloir (pinwheels coming off lookers right wall started around 11:30) top half took a long time due to deep snow so I was suspicious of the pinch. Ski cut it during the descent (12:30p) and set off a wet slide (point release) that picked up quite a bit of steam as it came out the bottom. Big enough to injure/bury a skier.

Moderate to strong wind at mid mountain level with visible transport across and down slope in many locations. Skiing conditions deteriorating in wind affected zones. 

From IG Message: "I read the avalanche report this morning and felt comfortable skiing. we made a plan to ski Bradley’s Meadows but ended up skiing Bridger Gully to the 3 Bears after discussion and feeling comfortable and confident in the snowpack. we did not experience any whoompfing or have any other concerns on the approach. 

The bottom of Bridger Gully to 3 Bears is where I triggered the avalanche. My partner dropped in first and skied safely out of the potential slide area. I followed up and on my first turn, triggered the slide. To me it looked like it was around 8” deep and was around 15’ wide at the crown.

My partner had eyes on me the entire time as the slide carried me about 40-45 yards. I was on top the entire time and was able to ski out at the end. I suffered no injuries. 

We skied out and talked to other skiers about our experience."

Saw a small avalanche on a steep roll over below the nose. Looked like it could've been human triggered.

Strong to moderate winds at middle elevations trending from the north but also swirling quite a bit. Active windloading observed on ESE slope at 7800ft

At 1:30pm on 11/23 I intentionally triggered a fresh drift of snow in a narrow avalanche path along the edge of the north bowl at Bridger. Northeast aspect at 7,600’ elevation. The crown was 6-8” deep consisting of snow that fell today, 20’ wide and ran 250’ vertical. SS-ASc-R2-D1.5-I. 

Wind was moderate, gusting strong out of the north and west and transporting snow. There were 3-4” on lower mountain and 7-8” new up high. Snowpack is 1-2’ deep. Prior to this storm, snow close to the surface had turned to small (1-1.5mm) facets during previous cold weather, capped by a thin crust (wind or sun) on many slopes. 

From IG message: "We saw a few decent sized point releases in the same zone on Sunday, 11/20, the day after the wind slab. All occurred on SW aspect within approx 15 min at 2:30. The air temp rose noteably shortly before and the sun was baking the SW aspect."

A snowmobiler noted cracking of the snow surface on the south face of Reas Peak out of Island Park. The wind crust was 3-4" thick and had facets underneath which aided the propagation.

During our trek up to Narcolepsy and the Champagne climbs, we observed a large amount of surface hoar atop the snow. There were large (1/4-1/2”) flat crystals growing from the snow sitting on a small icy faceted layer. It seemed to be widespread and was found throughout most of the canyon. We figured this may cause instability during the next snow accumulation.

En route to Narcolepsy, we encountered waist deep powder and very unconsolidated snow. Even higher up near the climb we did not find any evidence of wind slabs or consolidated snow. We did witness a small loose snow avalanche on a sun exposed slope with an obvious fan caused from the moving snow.

Went touring within Bridger Bowl's currently closed boundaries yesterday. The week of cold temperatures and lack of precip has done a number on the snow in terms of quality. Below the tops of PK and Alpine lift, all aspects have been wind affected. There is very little fresh snow available for transport anymore (at least below the ridge). I dug a little pit going up towards the fingers from PK. HS was 43cm. The base layer had a sugary, square-ish look to it, likely faceting rounds. The temperatures yesterday were mild and sunny and the winds were low. 

Loud pow, obvious near surface faceting on most slopes, thin breakable sun crust on S aspects, wind affected on unprotected NW aspects at ridge line, ECTX x2, lots of deadfall, still too thin in many places for enjoyable skiing