Snow Observations List

Saw lots of small loose avalanches on Mt Blackmore and nearby slopes, some appeared to be natural and others skier triggered. We saw multiple dry loose on N and E aspects and a wet loose on a southeast aspect.

We also noticed recent wind loading on the southeast side of ridgetops and scouring on north slopes.

Old Avalanche spotted from Wilson yesterday looking  North. Possible cornice fall trigger during the warm up but difficult to tell as it was quite a ways away.  Photo attached. 

Got up early and cruised around on some different aspects on Mt Blackmore. Got some shooting cracks on the N side of the mountain mid slope, textured snow and snow drifts were widespread in the basin on N aspects.  Found great skiing in N facing trees on that side of the mountain lower down below the apron and such.

East face had some top loading, nothing I was concerned about below ridge lines, save for some fast sluffs!

Found some isolated pockets of surface hoar, nothing widespread.

All in all, a fun morning, be curious to see how this next one affects the stability picture. 

Took a quite tour up The Ramp to see how the new snow is bonding. Found 3-5" of new snow. Non-cohesive and seemed well bonded to the surfaces beneath. No signs of wind effect. No slab avalanches or signs of instability noted.

Saw a few sluffs in the new snow triggered by skiers in the very steep terrain just north of the Bridger Bowl ski area boundary (see photo). These sluffs were small, definitely not large enough to bury someone.

We rode along Buck Ridge, dropping into First, Second and Third Yellow Mules. We looked into Bear Creek and McAtee Basin drainages before riding through Muddy Creek to the Yellowstone Club boundary. Throughout our ride, we noted tracks nearly everywhere, including many steep slopes. 

In nearly 45 miles of riding, we noted two avalanches. Both breaking on persistent weak layers a few feet down in the snowpack. The first was a small north-facing pocket in the First Yellow Mule (R1-D1) that was snowmobile triggered. It looked to be around a week old. The second was a larger avalanche (R3-D2), east-facing, deep in Muddy Creek. This was drifted in and likely broke around 2.5 weeks ago during the last significant storm cycle. We dug a snowpit near the lower flank of the path and noted that these weak layers had gained strength over time. We did get propagation on a stout melt-freeze crust near the surface (ECTP5) but did not get propagation lower down on faceted grains. 

Currently, these two PWL avalanches are the only PWL avalanches we have seen/have been reported to us in this area this season. This zone seems to be the northernmost extent of the PWL problem that we are dealing with further south in Lionhead, S. Madisons and S. Gallatins. 

Outside of these older two avalanches, we noted no other signs of instability and had a great day of riding. 

Dug a pit at 9650ft on a 20° NE facing slope near Zimmer Creek. HS 210-230. ECTN14 at about 40cm down.  

Skies were still blue with increasing clouds when we rode up into Fairy Lake zone this morning. We popped up onto the Frazier Basin ridgeline and could see many tracks from skiers over the weekend. As we descended back to Fairy Lake and transitioned to skis, the cloud deck increased and the ceiling lowered. We ascended up Nayu Nuki's east shoulder and at times visibility was limited to 25' in front of our ski tips. Temps were still quite warm and winds were minimal. 

Snow surfaces were variable with a mix of sun crusts, wind board, and in shallower tree-sheltered zones, sugary faceted snow. It will be interesting to see how well a few inches of new snow this week bonds with these different snow surfaces. 

While our original trip plan involved stepping out into steeper avalanche terrain, we decided to pull the plug due to extremely limited visibility. This was an example of how even though avalanche conditions may be generally stable, there are other factors to consider when choosing to ski steeper lines (visibility of your partners, visibility of surrounding avalanche terrain, etc.) 

Toured up Flanders Creek to the main cirque. I was wondering what the snow surface was doing with the high pressure. I dug a pit on a NNW aspect at 8900'. HS 205cm, light SW wind, clear skies and air temp was 2.1 C at 4pm. Dust layer was down 60cm from the surface.

I didn't get any propagating results in my pit and the snowpack was right side up. I did notice a strong temperature gradient in the top few centimeters of snow. I only found this on sheltered, shaded slopes with dry powdery snow. I did not find a strong temp gradient or facets in dense wind affected snow. Something to keep in mind if we get a big dump of snow in the near future.

Today we observed wet loose avalanches in steep, rocky terrain on the west side of Miller ridge. SW facing, 9500 ft

Ridge line just west of divide peak in Hyalite canyon

Saw a fairly fresh avalanche up Hyalite from the top of the Fat and Skinny Maids, I think that would put the avalanche in the Storm Castle Creek basin. North facing shady aspects were still cool and chalky, solar aspects were getting quite warm. 

Got an early-ish start to beat the heat and was on top of Elephant Mountain by 9am this morning. Skied the southeast bowl for our first lap, which was supportable and mostly good corn skiing. It was unclear when solar aspects were going to fall apart, but I wouldn't have wanted to be skiing that bowl much later than we had. Very light wind, few clouds, and strong sun made for pretty rapid warming. The north aspect held cold snow down to 7500 ft or so, though it is quite shaded. Shout out to the party behind us up top for allowing me to engage them in meaningful communication about not skiing on top of us. That dialogue was appreciated. Lots of ski tracks in high places, pretty fun to see. 

Pictures of two cornice triggered avalanches way up the South Cottonwood drainage that was viewed from Alex Lowe. Looks to be in the recent days, around 9,000 feet North facing.

Also a massive cornice that had cracked and was slowly making its way towards falling down. Cornice was around 50 feet long, and largely overhanging. On the standard ascent of the East Ridge of Alex Lowe, the skin track usually travels below this cornice while ascending to the ridge.

Natural point release avalanche observed from the YC. Occurred out of bounds on the South side of Pioneer Mountain. 

Snowpit attached from Mt. Republic today.  East aspect, 10,000'.

HS 165, ECTP22 at 65.  

No collapsing, no cracking, no avalanche activity to report.  

40 deg F at Fisher Creek SNOTEL today (9100').

Another day of warm temps and clear skies allowed us to cover a lot of ground in the Southern Madisons. We rode into the Taylor Fork, up to the weather station, to the top of Carrot Basin, through Sage Basin, up and over into Cabin Creek, and all the way up to the head of Red Canyon.

We spotted a few old avalanches. One in Cabin Creek that was triggered two days ago by snowmobilers on a N facing aspect. At the top of Carrot Basin, we saw a small avalanche (R1-D1) on a N aspect that likely broke yesterday on buried weak layers. We also spotted one cornice-fall triggered (R2-D2) avalanche that broke earlier this week in Sage Basin and then an older wind slab in Sunlight Basin. 

We dug a snowpit in Sunight Basin right next to where Alex and I dug last week. At that site on 2/21, we triggered whumpfing, shooting cracks and got propagation in our snowpit. Today we did not experience any of those signs of instability. Our snowpit showed poor structure with buried surface hoar and facets but yielded ECTN's on that weak layer. 

There were a handful of small wet-loose avalanches on solar aspects that we noted throughout the day. While northerly aspects stayed cold, solar aspects became wet a couple inches down. 

Despite no remarkable new avalanche activity and the stubborn reactivity in our snowpit, we remain wary of mid-elevation slopes steeper than 30 degrees. Over the last 12 days, we have received reports nearly every day of avalanches breaking on persistent weak layers buried 2-3' deep. Recent nearby avalanche activity in Teepee Basin and Lionhead is evidence that these weak layers should not be trusted quite yet. 

The travel advice remains tricky, but you have a few options:

1. Before committing to steep slopes, dig down 2-3' and assess for layers of buried surface hoar and facets. Make observations as you step off your snowmobile or skis or board - are you staying on the surface or sinking all the way to the ground? 

2. If you are choosing to ride steeper slopes, pick ones with less consequential terrain features like trees, cliffs or gullies.

3. The ol' reliable option: stick to riding slopes less than 30 degrees. 

Kicked off a wind slab avalanche 25ft wide on the west ridge of beehive basin. The wind slab was around 8-10ft deep and the debris slid almost to the flat a few hundred feet down the slope. The slide occurred around 9100ft on the east aspect. Neither me nor my partner were carried or caught in the slide. 

The windslab that broke off was about 8-10 feet tall. It was mostly a huge section of a cornice that broke and the slope it fell down onto seemed to propagate a few inches down as well. The majority of the debris was from the cornice.

Observed multiple wet loose slides naturally triggering and running on south facing slopes beyond bradleys and on the south facing aspects of hourglass chute.

We rode throughout most of the Lionhead area looking for and assessing a weak layer from late January. This layer produced avalanches last week that we saw. It also buried a rider last Sunday in Teepee Creek. It caught a ride yesterday in Cabin Creek.

• In most of our snowpits, the layer was gaining hardness
• In most of our snowpits, the layer was either not breaking in stability tests or was very stubborn. 

We were scratching our heads because the layer seemed active but we could find any evidence that it was still a major problem, UNTIL

A rider triggered a huge avalanche in the uppermost reaches of Targhee creek. We discovered it on our way out. The best we could tell looking at their tracks was that they had no idea they triggered it, even though part of their tracks were swept away. 

Also, on our way out we saw an avalanche in Airplane Bowl that had been triggered during the day today. This slide also broke on the persistent weak layers, 2-3' deep, 150' wide.

HERE'S THE DIMEMMA - On many slopes, the likelihood of triggering an avalanche on this weak layer is low. On some slopes, the likelihood of triggering one is high. Because the distribution of this problem is spotty, the damage is Moderate but that rating is deceiving. 
 

HERE'S THE OTHER CHALLENGE - You won't see any obvious signs of unstable snow like cracking or collapsing. You probably won't see any red flags in a snow pit. There will be no warning until an avalanche happens. 
 

TRAVEL ADVICE - We haven't been able to find a clear pattern for where these avalanches will happen and where they won't. It's a scary and tricky situation and these things are like booby traps. There are three options:

• Roll the dice and hope for the best, OR
• If getting onto steeper slopes, choose ones with a clean runout with no trees, rocks, or gullies and make sure your partners are watching you from a safe location, OR
• Ride only on slopes less than 30 degrees in steepness where most avalanches do not happen.

Wet snow - south facing slopes were getting very wet. We saw a few wet loose slides from yesterday near Targhee Peak. One south facing slope we crossed was wet for at least a foot or two into the snowpack. 

Just chiming in to report widespread wet loose activity on solar aspects between 6000 and 9500 feet in the Mill Creek area of the Absarokas - rollerballs started around 11am. Some big wet sluffs were releasing near cliff bands shortly thereafter. Felt like mid/late April.