Snow Observations List

Photos from email. Avalanches previously reported - https://www.mtavalanche.com/node/30013

From IG: “…, probably propagated a mile long, on a layer of advanced facets 30cm below a wind slab… We dug a pit yesterday and got a ct4,  ectp9, pst 25/100 on the same layer.”

From facebook message: "Multiple remote triggers across this slope."

Up Targhee Creek, near Lionhead Ridge. 1/18/24

Natural & remote trigger avalanches observed on most steep terrain. 

Alex and I began to dip our toes into a Saddle Peak stability assessment. Given the new snow and HIGH danger on wind-loaded terrain in the Bridger Range, we decided early to skip the summit and cross onto the edge of the Football Field from the Bridger Bowl boundary. Upper slopes had fresh drifts of wind-loaded snow and new cornice growth, but there was not as much loading as we feared there might be. We stuck to our conservative plan and skied the "Bitter End" (the closest run to the south boundary of the ski area) down to 8400' elevation before ducking out across the boundary. 

The snowpack is thin and weak, with advanced facets making up most of it. Our test results did not reveal obvious instability, just weakness (ECTX). It is unreasonable to apply that same assessment across the Peak. Human-triggered avalanches are certainly possible, especially in areas with thicker slabs of wind-drifted snow (something that is quite common to find on Saddle Peak). Given the very high-consequence nature of the area, we advise patience and conservative terrain choices and decision-making. 

115-120 cm HS @ 8250'

Temp in the low 20's.  Overcast until at least 3 p.m. 

West side of tree trunks snowblasted by wind, both on the south and north sides of the ridge into Pebble Creek.  

Experienced whoomphing starting at 8000', midway up the gully, south side of the ridge, where there was some wind deposition.  Parallel cracks 10' apart - looked like "stretch" marks.  Extensive whoomphing in the saddle and down in Pebble Creek Valley.  Ski penetration = knee deep, and trail breaking was a bit of work today.  18" new snow at 8250' and in Pebble Creek.  Snow was too deep for turns on mellow slopes, and too much collapsing to go steeper.  Occasionally broke through the hard layer, into the hollow below.  

Still windy in Pebble Creek (less than 10 mph), but definitely wind scoured.  Looked like a natural avalanche on SE facing slope of the ridge to the N of Pebble Creek.  

Coverage still slim down towards the highway.  

We skinned up towards Hyalite peak today to see how the snowpack was adjusting to this new load. While we did see some point release on the canyon walls during our approach, there was no collapsing and minimal wind effect below 9000 feet. As soon as we topped out into the hyalite lake basin, a northerly wind picked up and there were supportable wind drifts scatted about. Got an ECTx on a northern aspect at 9200' before deciding to ascend a 25 degree adjacent slope. About 50' from our pit we remotely triggered two D1 slab avalanches which broke on the roll over 150' above us. Crowns looked between 1-2' and 20-30' wide. The larger of the two ran 100' more or less. Yikes, time to bail! The low angle tree skiing along the skinner was quite nice.

North of Cooke City we observed numerous avalanches that likely happened last night or early this morning as snowfall stopped. Partly cloudy skies gave us a good view of the terrain and ridgelines. In the Fisher Creek drainage, we saw multiple natural avalanches on the east side of Henderson Moutain, including just south of Henderson Mountain off the Lulu Pass Road. At the back of the drainage, we saw another avalanche on the shoulder of Scotch Bonnet Moutain. Crown depths ranged in size but from afar seemed to be 1-2' deep. Several of these avalanches are wide and in sheltered terrain at mid-slope. 

On the other side of Henderson Moutain in the Miller Creek drainage, we observed avalanches in the gully near the Daisy Pass road. Along the east side of the Miller Ridge, we saw large natural avalanches that happened just below the ridge line. On the south side of Crown Butte, the story didn't change with two large avalanches happening mid-slope, and near the summit. Again these crowns ranged in depth from 1-2' deep and deeper on the south side of Crown Butte. 

On the west side of Henderson Moutain, we transitioned to skis and began ascending a low-angle slope toward a known avalanche path. Along the way, we experienced several collapses. Halfway up the slope, Ian noted snowballs rolling down the hill and around the corner, we could see the debris that had come from the steep terrain above. We had a clear view of this slope near the snowmobiles and it had not avalanched when we began ascending. At some point from several hundred feet away, we remotely triggered the slope. The avalanche was ~150' wide, 2' deep and ran almost to the road. Across the gully, we could see large cracks but the slope did not avalanche. Above, cracking and collapsing continued and we got a view into the upper part of the gully and saw another crown of an avalanche that likely happened at the same time as the slope below. 

Roads that were groomed last night and by 9 am had wind drifts that were a few feet in size. The snow has stopped but the wind remained blustery through the morning and into the afternoon. Getting on or under steep terrain today was certainly not in our travel plans, and it will remain that way at least through the weekend. 

More photos and video coming soon!

4-6" of new snow. active transport with increasing sw winds. NE facing ridge. 9200'.

Went for a short tour near bacon rind, next pulloff to the south, toured up the burned out hill right across the street. It was real windy leaving my vehicle. Some notable whoomphing, and cracks forming 30 ft around me. I probably won’t be riding down there for a bit, the low angle stuff I like is too thin. Real thin down there with only about 40-60cm on the ground. Got a CT1 SC  Q2 breaking about middle of snowpack, ectn 2, and ectp24. 

Moderate to Strong, SW winds were picking up this evening at Lick Creek, resulting in moderate snow transport along the ground. Previous drifts were building in leeward aspects and small terrain features, and I noted several areas of very dense wind board while skiing and touring. I also observed some local collapsing of these wind slabs around my skis, and would expect this issue to be exacerbated higher elevations by increased wind transport and the widespread presence of pwls. I was surprised by the amount of snow available for transport, especially at the relatively low elevation, and was glad to be in simple, low-angle, terrain.

Generally stiffer and more supportive wind slab in the upper snowpack overlying early season facets. Our approach track to Frazier basin was filled back in by wind load by the time we exited the zone( less than one hour)

We rode to the bottom of an avalanche on Sheep Mountain that had been triggered by riders from the bottom. This avalanche happened on Monday, 01/14, but by today it had been filled in by recent winds and new snow. From here we worked our way north of Round Lake and found 10"-12" of new snow (0.5" SWE), compared to the 5" of new snow near Sheep Mountain. Near the wilderness boundary, we found unstable snow and while getting a snowmobile unstuck in the flats remotely triggered a small avalanche from 100' away. We then rode to a northern aspect at 9600' and found 170 cm of snow and had poor results in our stability tests, with an ECTP 6 on buried weak layers below the last week and a half of storms. 
 

From here we rode to the top of Henderson Bench and dug on an east-facing slope at 9500'. While walking to our snowpit location we collapsed the slope and a small pocket of snow below a tree avalanched. Here we again had poor stability test results, ECTP 11, this area had previously been wind-loaded during last week's storm. Storm totals here were less than what we found north of Round Lake, with 5" of new snow at 3 pm (0.2" of SWE). 

Wind through the day was calm but is expected to increase tonight. Snow will continue tonight into tomorrow morning. Expect danger to rise as snow totals increase and wind begins transporting snow. 
 

From FB: Taylor’s Fork today, 8-10 inches of new snow last night. A few small slides but tons of cracking.

From email: "We skied a 25 degree west slope today on Woody Ridge.  No sign of instability.  No wumphing or cracking.  We all recognized the poor snow structure we were on and we pulled skins when the slope angle approached 30 deg. 5 degrees, at 100pm, light breeze.

HS 110-115 cm

new snow 30 cm. fairly cohesive but not bonded to old-variable

Layer of facets below new snow and above hard layer 60cm deep

Hard layer 10-15cm thick

facets below hard layer

The snowpack depth was variable.  New snow not well bonded to old snow in places we climbed to 9550 and stopped as terrain got steeper"

We skied a 25 degree west slope today on Woody Ridge.  No sign of instability.  No wumphing or cracking.  No wind effected snow, in forest

5 degrees,at 100pm, light breeze.

HS 110-115 cm

new snow 30 cm. fairly cohesive but not bonded to old-variable

Layer of facets below new snow and above hard layer 60cm deep

Hard layer 10-15cm thick

facets below hard layer

The snowpack depth was variable.  New snow not well bonded to old snow in places

we climbed to 9550 and stopped as terrain got steeper

Coverage was good.  Very good skiing

I might add that several times during the day we commented on the difference in red flags we experienced from Beau's report the day before. We were both S. of Cooke, but differences in that we were in wind-protected forest most of the day, although in meadows above about 9K, more importantly, perhaps is aspect - we were W. and I think from photos, Beau was on an E. aspect. Although we didn't get collapsing or shooting cracks, we all recognized the poor snow structure we were on and we pulled skins when slope angle approached 30 deg.

Average snow depth was only in the 110 cm range and the terrain we were in looked very different from that in a year with a normal snowpack. Sill some snow-snakes and staubs concealed barely below the surface.

Rode up Denny Creek and out along Lionhead Ridge through Watkins Creek to the divide with Targhee Creek. Saw evidence of numerous older avalanches along the ridgeline and in lower steep meadows that likely broke last week (1/10-1/11). The crowns of these slides were blown in, but would estimate they generally broke 1-2 ft deep. Some broke quite wide ~1000 ft. Saw a couple smaller slides that looked to be a bit fresher as well. 

Got a number of collapses and shooting cracks as we rode today, shooting out 20+ ft. 

Stopped and dug a pit at the crown of an avalanche that broke on the north end of ski hill (likely during last weeks warning). Broke ~1 ft deep, 50 ft wide and ran 100 vertical. Another similar slide broke at the same time on the south end of ski hill. Today, we got an ECTP12 on the surface hoar about a foot deep.

The snowpack remains unstable and human triggered avalanches (including remote triggers from a distance) remain likely. Expect the danger to rise as it snows over the next couple days. 

We toured into Mount Blackmore and up the standard route on the southeast-facing shoulder. Winds at higher elevations resulted in some drifting and there were pillows of recently drifted snow evident on the east face of Blackmore. We did not experience any collapsing, shooting cracks, or obvious signs of instability on our tour.

We dug at the top of the shoulder with unremarkable results (ECTN5 5" below the surface on a hardness change). The structure is very weak but it lacks a cohesive slab in many areas to push it over the edge toward instability. It is possible to trigger an avalanche on slopes with recent wind-drifting or where a thicker slab is resting on persistent weak layers. Avoid wind-loaded slopes and you will minimize the chances of finding a trigger-point. 

With snow on the way, we expect to see the danger rise in the coming days. Recent avalanche activity, collapsing, and shooting cracks are all reasons to chose travel on slopes less than 30 degrees in steepness. 

Wind slabs at the top of the ridge approximately 4-8 inches deep. Continued wind loading down the wolverine bowl, slabs softer the lower you go. Snowpack has about 1.5 feet of facets with a hard layer on top. New snow building up on top of that layer. Saw one small natural avalanche nearby, appeared a day old.

On my tour up the main fork of Hyalite today I noticed two slides near Divide Peak caused by wind loading.  There was a wind skim on all snow surfaces in the Basin and I experiences a bit of collapsing while walking across the basin in the flats on small wind loaded pockets