Snow Observations List

Near Cooke City on 4/19 skiers triggered a dry loose avalanche and a small wind slab avalanche. The wind slab broke in a drifted pocket near the base of cliffs, 3-6" deep x 10' wide. Northeast aspect, 10,200'.

Today (Saturday, 4/19), I triggered a small soft-slab avalanche at about 7,700' on a E-NE aspect on the headwall between Frazier Lake and Angier Lake in the northern Bridgers. The slide was maybe 6" deep, 20' wide and ran 100-200 feet and involved only the new storm snow over the icy, thick crust underneath. No one was caught or injured, though I had a bit of a scare because my dog was right in the path (luckily she outran it). We had gone up with the intention of skiing the Ainger "Love Chutes", but bailed partway up when that whole aspect turned out to be breakable crust. However, we had beta from another party that conditions on the Frazier-Angier headwall were good, so decided to check that out. We skinned up without incident, following a well-set skin track that followed the line of least resistance; snow surface was variable but seemed stable. Coming down, we mostly followed the ascent route, but towards the end I was tempted onto a fun-looking, untracked stash a bit to skier's left, that seemed only a tad steeper than the ascent line. A few turns into this line is when I triggered the slide, right at the steepest part (mid-high 30s). It definitely took me by surprise given that we'd been skiing great, stable powder in the Bridgers the past couple days. No harm done but definitely a good wake-up call! 

Meant to submit this yesterday (4/18), saw this one wet loose slide that naturally started off some rocks. Decent size by the bottom. Other than that, just some spiff. Surprisingly didn’t see any big wind slabs trigger, despite the widespread wind effect in the northern Bridger’s. Lots of wind scour on southerly aspects. Northern aspects had wind loading. 

We rode up to the old weather station and then to the current weather station, down Airplane Bowl, along the base of the LH Ridge to the head of Targhee Creek and back. There is a 4-5" Thick refrozen crust below 3-5 inches of new snow at upper elevations. At lower elevations, there was less snow, and I suspect more rain, and east winds stripped many of the upper starting zones back down to the melt-freeze crust. 

There was little, if any danger of avalanches today. You may have been able to find an isolated wind slab from the east wind-loading, but it would have been small in area and depth. We rode out at 2 PM and the crust had not started breaking down in any meaningful way. 

Tomorrow is supposed to be 8-10 degrees F warmer, but cold temperatures tonight should refreeze the crust, and it is pretty robust. There may be a few very small, wet snow avalanches in the recent snow with warming temperatures, but I would not be particularly worried about slides. There is more snow and colder temps forecast for Sunday and Monday. Fingers crossed for a bit more powder riding. 

The road from the Buttermilk TH was reasonable but is melting out quickly. There were a few dirt patches that will grow tomorrow. 

Beautiful day to spend in the mountains and the riding through the upper bowls was quite nice. 

Toured out Deep Creek to Zeppo’s. Summer trail was largely melted out in the drainage. Despite warm temps and sticky, wet snow on E-S-W aspects, we still found about 4-10 inches of dry new snow over a MF crust on N aspects above 8500 feet. Snow in the Zeppo’s burn was holding up surprisingly well from the previous night’s freeze and was supportable through the afternoon. Large cornice formation on E aspects. 

We went through Flanders' Creek to the Flanders Weather Station to pull it for the season. We descended to the Grotto Falls TH via the Winter Dance Route. The surface snow got wet as the day progressed, but we saw no wet snow avalanche activity. I wouldn't be surprised if there was limited activity as the day progressed.

Recent warm temperatures have almost universally affected snow surfaces. North-facing slopes above 9500' elevation remain dry, and pockets of dry snow exist at lower elevations on shaded slopes. South-facing slopes have cycled a few times, and the corn snow is coming in reasonably well. 

There were no signs of dry snow instability.

We found soft snow on north-facing terrain in Sac Bowl and off Pomp Peak, skiing until about 2 p.m. on 4/14. The recent storm winds stripped some southeast facing terrain down to crust, but had deposited 4-6 inches of creamy pow in sheltered N zones. Skiing was mostly bomber, with the exception of some wind slab we avoided on a start zone immediately below ridgeline in Sac Bowl. Saw a few small dry loose / point release slides in southern Bridgers, but nothing in N. Bridgers except for old debris piles. 

I rode the motorized zone and noticed natural wind slab avalanches running pretty far on: East Henderson, SE Scotch Bonnet, East Miller, NE Crown Butte. D1.5-2.0

Loose wet debris from yesterday were also present in many places. 

Screenshot of winds from Lulu Pass wind station during the storm.

Today I was skiing in East Hayden Creek. I witnessed a cornice fall around 1230pm. Also I triggered multiple wet loose avalanches on several aspects including a north facing slope 9400 ft. None bigger than D1

I rode into Fairy Lake. There was 2-3” of new snow above the elevation of Fairy Lake, a trace below. Winds were cranking at ridge top elevation, transporting what soft snow there was. Minimal hazard formation. I spotted one fresh wind slab avalanche near Hardscrabble. The slide ran several hundred feet in steep terrain but was very thin (R1,D1). 

There was a mostly supportable crust below the new snow about 1” thick. The snow below the crust was moist. 

Found some reactive fresh windslabs that were on northeast terrain  features yesterday Wednesday 4/9 easily triggered with a very small cornice we dropped in the northern Madison range, the pocket slabs didn’t propagate super wide but did pack a punch and were up to 1 ft deep.

Roaring wind, graupal, low to no visibility. 3-5'' of mixed snow forms. Skiing was surprisingly good and wind slabs generally unreactive, but I was just on lower Fisher, right below Lulu. Picture is South East on Scotch Bonnet 

Today A Skier triggered a 6”x20’ wide wind slab on a N aspect at 9,800’.

Skiers triggered D1-D1.5 wet loose on SE aspect at 10,000’.

There were also natural small wet loose slides today and yesterday. Long running, but narrow, in steep terrain. Typically initiated near rock outcrops.

Today was hotter than yesterday and the top of the snowpack got pretty wet before clouds built in the afternoon. Snow stayed dry on due north up high. 

We rode into Fairy Lake and climbed up to the Great One. Surface conditions ranged from gloppy, wet snow to firm, dry wind slabs with very little powder in between. There had been a fair amount of wind-slab and wet loose avalanche activity in the area over the weekend, but things were quite today. We had a report of a human-triggered wind slab avalanche in the Great One on Saturday. 

By 11:00 AM a layer of high clouds moved overhead and limited the melt-down input from the sun. Ambient temperatures reaching 50 degrees F didn't do the snow quality any favors at mid and low elevations but additionally didn't result in any natural wet snow avalanches that I saw. 

Wind-slabs were relatively thin (a couple inches to 8" thick). We did get cracking in a few drifts that was limited to the area directly influenced by our skis. We dug at the top of the Great One with unremarkable results and proceeded down the run. 

Tomorrow looks to be cooler with limited snow accumulation. If this forecast pans out, triggering an avalanche will be unlikely. Let's hope for more snow than is in the forecast!

While touring south of town today, we observed two D1 wet loose avalanches on an east aspect at 10000’. Both occurred at 11am and were triggered by a small cornice fall due to rapid warming.

We skied near Henderson Mtn. and Lulu Pass. Skies were clear with a light breeze near the ridgelines. Temperatures stayed below or just barely above freezing.

We saw a couple 3-6" deep natural wind slab avalanches and a few dry loose slides that looked to have happened within the last 24 hours. On southerly slopes below 9,000' there were some wet loose slides from yesterday afternoon. 

Wind slabs were still reactive today. We triggered 3 small, 3-8" deep x 5-15' wide, hard wind (1F+) slabs on convex test slopes well below the main ridgelines. 9,800', NE aspects. Also triggered one softer (4F) wind slab just below the high ridgeline, 10,200', NE aspect. 10-15' wide x 6-8" deep.

Snow stayed dry on northerly/shady slopes. Any sunny slopes got moist and had a crust formed by late this afternoon. We did not notice any fresh wet loose slides or roller balls on southerly slopes above 9,000'.

Stay alert for unstable drifts of snow, wind slabs formed last week are still breaking. Anticipate wet snow hazards to increase in size and distribution as the days get hotter this week.

We snagged an early morning tour to avoid the heat today and it (mostly) worked. We saw no avalanches, cracking or collapsing while out. 

-We found a 2-4cm thick breakable crust on SE, S, SW, and W aspects that probably formed during Friday’s sunshine capping 6-10” of fresh snow above 9k’

-There was much less fresh snow below 9k’ (baked off?)

-Northerlies held stable soft snow!

-Small natural dry loose activity started around 11am on steep NE and E slopes initiating from around rocks/trees

-We sniffed out some south facing corn, but it was generally grabby/sloppy wherever a few inches of recent fresh snow remained

A snowobarder tagged us in an IG story of triggering a long running, powerful wet loose slide in the Bridger Range.

We went on a tour in the Bridgers today, we ascended the east ridge of Naya Nuki to the entrance of the Great One. Wind was blowing and we were being careful about potential wind slabs up high.

Skier 1 ski cut the top of the chute and produced a small wind slab that ran to the break in the chute and continued another 100 vert down the east apron. After all meeting up halfway down, skier 2 proceeded to ski the E facing apron. A wind slab propagated and carried skier 2 roughly 300 vert down the apron where skier 2 was able to swim out of the fall line and came to a rest on top of the debris. Everyone was okay aside two missing ski poles.

On the way out, we saw a few more small natural wind slabs that broke naturally near ridge lines as well as point and release wet slides.