Snow Observations List

Natural avy on SE aspect 8000 ft 35 to 40 degrees. Broke on new snow interface today. YNP next to Silver Falls.  Also several slides in gully below falls.  

From IG:

Made it out past round lake around 11am this morning - dug multiple hand pits  above 9400' to gauge new snow depth - 40-50 cm new snow from this storm, very light, over the hood riding!  Minimal wind below alpine, upper 20cm new snow collapsed easily in hand pits, very little cohesion in the new snow.

Observed several smaller avalanches, all in new snow, undetermined whether natural or ridder triggered, attached photo of the only slide I could get an alright photo of, vis was limited. 

We went back to Buck Ridge to see how the big load of new snow was reacting. Rode through 1st, 2nd, and 3rd Yellowmule. Measured 13” of new snow with 0.6” SWE in 1st Yellowmule at 10 am. This brought the two day snow total to approximately 20”. Snowed all day with varying intensity and there were strong west winds along the ridge. 

Visibility wasn’t great, but we saw most of the avalanche terrain in the Yellowmules. Saw one avalanche along the 2nd Yellowmule headwall that broke 100-150 ft wide just under the new snow (maybe 1-2 ft deep, it was hard to tell). Also saw a very small snowmobile triggered avalanche on a roadcut on the way out (6-12 inches deep, ~20 ft wide) that broke on facets in the thin snowpack. Rode many test slopes and got only very minor cracking. The new snow just wasn’t slabby even in the many places where it was wind affected.

With so much new snow (and having issued an avalanche warning), it was an easy decision to avoid all avalanche terrain today. Even after it stops snowing (likely sometime tonight) conditions will remain unstable and avalanches will be easily triggered for several days. The buried surface hoar layers will take longer to stabilize than new snow instabilities would by themselves. 

ECTP 3. New snow slab. No other propagation. 

Observation Date:

January 26, 2023 - January 26, 2023 

Submitted:

January 27, 2023 

Observer:

RRS - Kevin Allred 

Zone or Region:

Island Park 

Location:

Mount Two Top (NNE 7680')

Signs of Unstable Snow

Recent Avalanches? 

 None Observed 

Cracking? 

 None Experienced 

Collapsing? 

 None Experienced 

We Traveled to the Two Top area. Due to low visibility and new drifting snow Our snow pit location was in a lower tree covered elevation. We observed a surprisingly strong snowpack void of the obvious buried SH layers we found higher. With new snow available for transport and strong SW winds we observed wind loading on NNE aspects in the area. 

Snow Stability

Stability Rating: 

Good 

Confidence in Rating: 

 Moderate 

Stability Trend: 

Worsening 

Bottom Line

The Buried SH layers are still present especially in higher elevation open slope areas. With the arrival of new snow, accompanied by strong winds the potential to form a wind slab over a PWL (Buried SH) could have serious consequence to riders in this area.

Advanced Information

Weather Summary

Cloud Cover:

Obscured 

Temperature:

15° 

Wind:

Strong , SW 

New/Recent Snowfall:

1 inch of new snow reported from the previous night. 

Winter storm warning had been issued for the area. 18'' of new snow in higher elevations followed by strong winds. We observed new snow available for transport at all elevations 

Avalanche Observations

Avalanche Observation Comments:

None observed

Snowpack Observations

NNE aspect 7680' HS 175cm CTN

Avalanche Problems

Heightened awareness of increasing avalanche danger with the arrival of this storm.

Terrain Use

Our travel mindset for the day, to not travel in avalanche terrain over 30°.Due to low visibility, blowing and drifting snow our travel plan was impacted and our route was shortened. I learned later of 2 riders in the Keg springs area that dropped into Carrot canyon unable to get out due to a damaged Snowmobile they where rescued by Clark county SAR 03:30 this morning. All where cold tired but SAFE! A big thanks to Clark County SAR A reminder of the dangers of back country travel

Toured up between Flathead Pass and Ainger Lake/Bollywood Headwall. Three pits at different elevations and aspects summarized below.

Pit 1:

7600', E aspect, HS 100cm, ECTX, uploading full pit profile on SnowPilot. Poor structure but as of now a stable pit result. Could change quick with additional load.

Pit 2:

8100', NE aspect, HS 160cm, ECTP28@120cm (in hindsight performed test on deeper side of column, still got an unstable result)

Pit 3:

8100', SE aspect, HS 90cm, ECTP22@30cm

Overall obs; soft snow in sheltered areas, particularly on E-->SE aspects above 7600' (and quite good skiing!); wind blasted crust on exposed N aspects and on ridge lines; below 7600' was very much survival skiing w/ bottomless facets and breakable crust (not such great skiing...); wind slabs on leeward slopes ~15-20cm thick, subtly stiffening through the day and shooting cracks ~5' from skis where wind slab present; strong winds out of generally the NW; cloud ceiling ~8400', ridge line was just barely obscured.

Low angle pow skipping was excellent from ~8100' to 7600'. 

Skied from the summit of both Palace Butte and Maid of the Mist.  Based on seeing no signs of snow instability and good terrain selection we had a grand day in the mountains.  There was approximately 25 cms of new, dense snow.  The SW Montana faceted snow at the ground resides every where we skied and snow above this layer is obviously well bonded.

We rode in through 1st, 2nd, and 3rd Yellowmule. There was 5-8” inches of recent snowfall. The only signs of instability we observed was some minor cracking in a drift at the entrance to Second Yellowmule. However, the problem is lurking just under the surface of the snow. Depending on the location, we found one to three layers of surface hoar in the upper 20” of the snowpack. At the top of Second Yellowmule we found repeatable ECTP1s and 2s on a layer of surface hoar 6” below the surface and repeatable ECTP 11s and 12s on a surface hoar layer 18” deep.

The depth and number of weak layers is somewhat irrelevant. The upper snowpack is on edge. Currently, human-triggered avalanches are likely on wind-loaded slopes. We choose to stay clear of avalanche terrain today. And, if tonight’s storm produces as forecast, we will be looking at an avalanche warning by tomorrow morning with natural and human-triggered avalanches likely to very likely. These could fail across wide sections of slopes and be triggered from a distance. We are preparing to stay off steep slope and clear of the runout zones.

We toured into Beehive Basin for field day 3 of our Pro Avalanche 1 course. We chose to avoid all avalanche terrain today on our ascent and paralleled the private boundary to reach the ridge on the East of Beehive Basin. Each member of our group then completed a full pit profile just below the ridge on W aspects. My pit was dug on a W aspect at 9,012 ft on a 20-degree slope. No active wind loading was observed at the location of my pit. I found snow instabilities approximately 30 cm below the snow surface on a layer of very large-grained surface hoar (CT8 Q2, ECTP2, PST 75/100 End). There were two additional layers of surface hoar buried deeper in the snowpack, although these layers were not reactive and showed signs of rounding and sintering. The basal facets in our pit are rounding and gaining strength and we did not find any instabilities deeper in the snowpack. We would expect to see natural avalanche activity on wind-loaded slopes that have this layer of buried surface hoar if we were to tour into this zone again tomorrow. 

We rode up Denny Creek and over toward Watkins Creek, etc. We observed two recent natural avalanches that broke 1-2 feet deep, presumably on a surface hoar layer. There was a couple of inches of snow on each of these slides, so I would place them between three and five days old. The slides were R1-D1.5 in size - 75-100' wide, 1-2' deep, and 100' vertical fall. 

We dug a quick pit with a snow height of 120 cm (4 feet) and found one layer of surface hoar buried 5" deep (ECTP2) and 4 Finger + facets near the ground (ECTP26). We were not concerned about natural avalanches today, but they will be a concern with a few inches of new snow or more on any slope on which the surface hoar is present (assume it is everywhere at Lionhead).

My ski partners and I toured up Flanders creek today and found 9"- 11" of new low density snow. We dug a pit at the base of the SE bowl of Flanders at 9500 ft. The snowpack was 90 cm deep, slightly shallower than what we found on Divide peak last weekend. We found that the new snow was sherring easily in hand pits and we got an ECTP 6 on this interface in our pit. The layers beneath the new snow were faceted junk but not reactive in our tests. The new snow sitting on a firm crust layer was our main concern. 

We toured into Beehive for day 2 of our AAI pro 1 avalanche course. We decided to tour up the ridge between “Going Home” and “Tyler’s Run”. We dug three pits as a group on a W aspect at 8700 feet and found generally stable results with no prolongation observed in any of the three pits. We did find a layer of buried surface hoar approximately 37cm below the surface, but evidence that the surface hoar has begun to break down, sinter, and gain strength. We found approximately 10-12in of new snow at elevations above 8,000 ft, which was more than we were expecting. Light snow continued throughout the day with 2-4 inches of accumulation by 2 PM when we returned to our car. We observed light wind transport at the ridge line, but did not find any wind affected snow on the W aspect that we toured up. 

An ice climber across the valley observed a large natural avalanche running over Silken Falls ice climb on the east side of the Main Fork. Wind was blowing and moving snow all day. This gully gets wind-loaded and was the site of a fatal avalanche in 2009.

My partner and I were out in a zone south of the bacon rind trailhead today and found some good snow. All of the laps we took today we N NE facing slopes and the snow was supportable and generally stable. We were riding on elevations from 7950 to 7200 all day, and only dug one pit but things were encouraging. I did not do a full profile but we did the usual tests. The total snow height was around 110cm and we got a CT14 Q3 and ECTN12 Q1 both breaking in the now snow around 95cm. Without doing crystal ID and differentiating layers I only got a general hardness scale, from top to bottom it was F-4F-1F+-1F-1F+-4F-G with the section near the ground seeming to be weakening. Overall the snowpack was encouraging but we still kept our riding to lower angle slopes focusing on some pillow lines. No surface hoar was found throughout the day and by the time we left the snow started to fly and the wind stayed light blowing to the northern end of the compass. No recent avy activity was seen on the surrounding slopes. Good snow and good vibes. Thank you all for your hard work, the community appreciates and values what you all do every day!

Had some cracking, collapsing of wind drifts up high on the ridge today and few Dry Loose slides running into Wolverine.

Winds were swirling, and coming from the south when I was skiing, but obviously the storm pattern is moving from the north.

Super wind scoured slopes from yesterday not bonding well in other places.

We found bottomless facets on the ski up through the low elevation trees. Once we got close to the ridge we dug a 130 cm pit that was completely unsupportable. It was just layers of facets on facets, ECTX. We then skinned to the top and dug another pit HS100cm, CTX, ECTN25 about 1.5 feet down. There was a supportable slab here and stability was still good. Once this area gets wind and snow I think the danger will bump up quickly. There is so much weak snow around I have a hard time believing it can support much additional weight.

We toured up to the Skillet today. We dug 7 pits on our way up. We found surface hoar buried 6-10” below the surface in all of our pits. This layer failed (ECTN 11 and 12s), but it did not propagate. At this point we were thinking about skiing the Skillet. We dug a pit at the top of the chute at 8,900’. The buried surface hoar was present in this pit, but it did not fail in the ECT. We had an ECTP 22 in facets 2.5’ below the surface of the snow. Because of this result and the terrain traps in the Skillet, we changed our plan and took a more conservative route down. Looking ahead, the buried surface hoar is the primary concern in this area. When we get more snow on top of this layer, instability will increase.

Dug on a sheltered N aspect at 9,000 feet below Alex Lowe Peak. Performed an ECT with results of ECTN 12 at 30cm deep and ECTP 21 near the ground.  
 

We also observed widespread sluffing of the new, low-density snow throughout the day, as well as increasing wind transport in the afternoon. 

Location. North of Hebgen lake 1/2mi east of white peak.
Elevation 9200ft/ Aspect S

moderate winds with strong gusts. Isolated wind slabs observed.  
 

HS 140

Compression test

CTH4 RP @115. CTH9 BRK @40