Snow Observations List

Saw multiple large slides around the McAtte drainage N/NE aspects. Some were larger than others but all ran on what looked like a persistent grain or even to the ground in some. Probably natural released over last few days.

During our time out the wind was hammering the ridge and clearing transporting and forming slabs. 

Several small slabs pulled out above The Shimmy, left of Cleo's. Observed from across the valley while climbing the Dribbles. Did not observe them run, only saw the crowns. Unknown date of avalanches, but crowns were quite distinct from across the way.

Lots of wind transport all day.

We rode to the south shoulder of Scotch Bonnet, then over Lulu Pass, towards Round Lake behind the north end of Sheep Mtn., and back to Lulu Pass. It was snowing very lightly and wind was blowing strong. Wind was blowing snow into drifts 6-8" thick on the leeward side of trees and convexities. We had intermittent ok visibility and could see old debris from last weekend on east Henderson, and we got a pretty good look at the slides on Fisher Mtn. that were triggered yesterday. They appeared 2-3 feet deep, and the debris was very hard. Crowns were already at least half drifted in.

We saw another slide on the north end of Sheep Mtn. on a slope above the steep chute where people climb out of Goose Creek (photos attached). This slide had not been reported previously and looked similar in age to the two triggered yesterday, so maybe broke naturally or human-triggered in last 24 hours. It broke near a scoured north facing ridgeline, 1-1.5' deep, 175' wide. HS-R3-D2-O.

We dug a pit on the south facing shoulder of Scotch Bonnet and had an ECTP24, down 1.5 feet, not on the previous layers of concern which were lower down (pit attached).

Regardless of stability test results or which layer slides are breaking on, recent avalanche activity and more wind-loading is enough evidence to avoid avalanche terrain.

Large slide in the north basin of fan mountain. The flies is below the north, north east couloir and the crown runs all the way around the basin. It went to the ground below the couloir and a few other places. 10ft crown probably at the biggest point below the couloir. 
 

no photos due to poor camera

Observed signs of a large avalanche along West aspect of Lionhead.  I am not sure when it occured.  At this distance and my experience level I can only estimate the crown at 3-4' and 1000'+ feet wide.  It appears to have run about 650' vertical feet and the runout zone goes all the way to Targhee creek into several terrain traps. 

We noticed that a widespread crust had formed at lower elevations from the recent warm spell, especially in areas without consistent shade. The snow that remained available for transport was easily being picked up by moderate to strong SW winds at treeline. Many tracks had been filled in by the wind transported snow, and a dense, hollow windslab was found in isolated spots.

The snow ranger crew was out in the Bridgers today, mostly lower down in the Throne and Naya Nuki areas.  The wind was very strong all day long and even in the woods our tracks were filling lightly from wind transported snow.  We could see a fair amount of snow blowing over the ridge top and some very textured looking snow higher up.  We did not see any recent avalanches.  

North facing aspect above McAtee creek.  Triggered one remotely while traversing below, ~150 yards away, and likely triggered the second one from below as well but cannot confirm. 4-6 foot crowns, 50-100 yards wide, ran 75-100 yards

One slide seems to be natural.

just around the ridge, lookers right, a snowmobile triggered slide

rider in photo. Rider was carried downhill, not buried. Very very lucky

the two slide seem to have happened at the same time

We skied Texas meadow this evening, and found relative stability. We tested a small hand out which did show the poor snow structures that the rest of the area with a very cohesive top on a sugary base, but we didn't find wumphing or other signs of instability in this zone. Southern aspects did have a strong sun crust on them, while others had great snow. There was also very gusty wind from the south which made temporary whiteouts and could be transporting snow. 

We rode up to the Indepedence Mine area (outside our advisory area) to check out the snowpack conditions before the Poker Ride this Saturday. As we arrived in the basin we saw a good sized recent natural avalanche. This really tells you all you need to know - recent avalanches are the clearest sign that triggering more avalanches is possible.

We then dug and confirmed that the snowpack is just as weak as it is across our advisory area. Two feet of fist hardness facets at the ground with almost four feet of slab above them make for a very weak structure.

If you're headed up for the ride this weekend I'd advise avoiding riding on and staying out from under slopes steeper than 30 degrees. 

We toured to the east shoulder of Divide Peak today, 02/22/2024. We saw several natural avalanches on the north-facing terrain in Divide Cirque, below Hyalite Peak, and Overlook Mountain. These avalanches likely happened following a storm near the end of last week. Near the base of Divide, we dug on a SE-facing slope at 9300' and had a stability score of ECTP30. From here, we continued up the shoulder, trying our best to stay on slopes near 30 degrees in steepness. At the top of the shoulder on an east slope at 9600', we dug another pit and found 133 cm of snow and had a stability score of ECTP20. In both our snowpits, we had a well-defined layer of weak faceted snow buried 2-3 feet deep. This is the layer our stability tests failed on. 

During our tour, we saw no cracking or collapsing, but recent natural avalanches near us and the large natural avalanche seen on Mt. Bole a few days ago encouraged us to keep our terrain choices conservative. We skied down near our skin track one at a time and avoided areas with terrain traps like gullies, cliffs, and thick trees below. 

My brother and I toured into the skillet at Bacon Rind. We dug a pit at the top of the skillet, east aspect, 9000 feet. Total snow depth was 115cm. We observed CT14 and ECTP25, 2.5 feet or 75 cm down, propagating on large old facets below a hard slab. That slab was dense and carrying some energy when collapsed in our column tests. We also observed multiple suspected week old natural avalanches on northeast aspects.

From instagram (2/23/24): Wide collapses and cracks reported near Palisades Falls above the east fork Hyalite road. 

We went back to the Throne today and toured up to the ridge where 9 days ago Dave and I experienced a large collapse prompting us to decend our skin track. During our ascent, we had no signs of instability such as cracking or collapsing but were still cautious while walking through steep terrain. On the north side of the Throne, we found a shallow snowpack, 63 cm, and saw a stability score of ECTX. On the south side, we found a slightly deeper snowpack and again saw a score of ECTX in the snowpit. 

We felt good about going into this terrain for a couple of reasons. First, this area has had only a few reports of recent activity activity. Second, there was a clean runout below and the slope was barely over 30 degrees in steepness. All of this in addition to seeing no signs of instability and our stable test scores made us feel comfortable skiing from the top while taking a conservative approach and skiing one at a time. 

Photo of an avalanche observed yesterday (2/22) on the SW face of Sawtooth Mountain at about 10,600’. Looks to be a few days old, but hard to tell since all skier traffic from the weekend has been erased with Tuesday’s wind/precip. If you look closely, you can see the crown extends across the entire face.

Long tour up the Noble Fork yesterday. The two feet of recent snow have much improved travel conditions. I noticed no bullseye signs of surface instabilities, asides from some old crowns on a very steep, north facing slope at treeline (~9000'). There was also some localized collapsing in windboard at higher elevations, and lots of rollerballs releasing from cliffs with solar aspects. I did not have time for a pit, so focused on avoiding connected avalanche terrain, and the runouts of larger solar paths.

These avalanche were noticed yesterday morning (2/20), possibly happened on 2/18-2/19.

NW aspect, 13 degree slope, 7850 ft elev. 

Total snow depth of 120cm

ECT X

Shovel Sheer (Hard) at 74cm

 

My ski partner triggered a big collapse/woomph from the our skin track, heading up from WY Creek back toward Republic Creek on an W facing slope. It was the second time we worked over this skin track, and it propagated to where I was at least, about 30 yards above them. I felt/heard the collapse 1/2 to 1 second after they triggered it.

It was snowing most of the afternoon in WY Creek with moderate winds with strong gusts at the ridgline coming out of the Southwest.