Snow Observations List
We rode portal creek meadows as an exploratory mission as neither Kyle Marvinney nor myself had ventured there much. New snow from the previous storm cycle had settled to about 4 inches, but it was hard to tell due to widespread wind effect. Judging from the snow, temps up there have mostly stayed below freezing during this previous warm cycle (after Monday/Tuesday storm), though there is fairly supportable crust below the storm layer. winds were blowing consistently 10mph up high gusting to and estimated 25mph. We observed one small avalanche in the riding area that occurred before the recent storm cycle and seemed characteristic of other similarly sized avalanches we have been observing throughout the season.Full Snow Observation Report
We rode into Lionhead with the USGS and USFS snow chemistry, hydrology and soil science teams. At the top of Ski Hill we dug a snow pit and in stability tests we got an ECPT27, that failed on weak snow near the ground.
From here we rode to Motor Hill via Denny Creek. While crossing below Lionhead Ridge we saw an avalanche in Airplane Bowl that likely happened a few days ago. This avalanche broke 12” deep and 100’ wide.
Above Motor Hill we dug another snow pit on an easterly aspect at 8600’. We had unremarkable test scores of ECTX (twice) and a PST 63/100 end. We saw a similarly poor structure as our previous pit, with weak sugary snow low in the snowpack.
This morning with better visibility we stopped at the Hebgin pull out and were able to see 3 recent avalanches along Lionhead Ridge that were likely the result of recent wind blown snow.
Our snow pit results above and the lack of deep avalanche activity were encouraging and initiating failure is becoming more difficult. This will change with incoming snow and wind so expect the avalanche danger to increase. This storm will hopefully test the snowpack and we are curious to see if it results in widespread avalanches or is able to support the new and wind drifted snow.
Full Snow Observation Report
This snowpack can take 1” of water before going to a warning.
This is somewhat irrelevant with the incoming storm but the danger seemed closer to Moderate than Considerable today. Initiating failure was hard and there wasn’t evidence of recent activity following the last storm. We will see what this storm does but long term discussing Moderate danger seems appropriate.
Toured up Republic Creek today. Went to the ridge below Republic Mountain and then to Woody Ridge.
winds picked up throughout the day and by afternoon were moderate gusting to strong at treeline and ridge tops from the W,SW.
started lightly snowing around 1 pm.
observed 2 crowns in wind loaded terrain. One at the end of Woody ridge on a north facing sub ridge (Peterson’s prow ) and the other on an East facing Ridge seen from the top of Wyoming bowl.Full Snow Observation Report
Rode Sawtell past two days. Very wide spread stout slab formed under the new snow that’s fallen. Heavy winds have scoured new snow away in places and deposited pillows in other aspects. Dug a pit with ECTX results but did not two layers of concern. One thin buried facet layer about 60cm down and the thick melt freeze about 80cm down. HS was 160 on a SE aspect about 8300.Full Snow Observation Report
Skiing some dog pow across Hyalite reservoir between 7200-7800’ on a NE pitch I got lots of whumphs and shooting cracks while braking trail. This was a shallower snowpack than most other areas, it was still easy to break into basil facets with skis on.Full Snow Observation Report
I was skiing inbound at Bridger Bowl today and noticed a small wind slab avalanche that failed on quarter saddle. I estimate comparing the photo to Google Earth that the slide ran 250 vertical feet and broke 100+ feet wide. Ongoing wind-loading and obvious instability.Full Snow Observation Report
We exited Bridger Bowl ski area via the gate at the top of the Alpine Lift, ascended Bradley's Meadow and The Ramp and dug in one of the Refrigerator Chutes on a NE aspect at ~8000 ft. We found a snowpack that made us pretty hopeful about the direction things are headed in the Bridger Range. Snow depth was 160 cm and we got ECTX results. At least in this location, the weak layers are starting to heal. The early January weak layer was 1Finger hardness. We are not at all confident yet about how widespread this is, but nonetheless, it is nice to see things getting better somewhere.
Winds were calm below the ridgeline, but we could see big plumes transporting in Wolverine Bowl. Yesterday's skin track was completed drifted in in some places.
Around a foot of new snow from the last couple days made for good riding conditions.Full Snow Observation Report
Touring from 6800' - 8800' breakable crust - both directions! Lots of whumphing down low but then none above 84-8600'.Full Snow Observation Report
From email: "We didn't see any avalanches on E Henderson or E Sheep with decent vis on the ride in. One large avalanche on a heavily wind loaded slope below a huge cornice north of Scotch Bonnet. That one looked like it broke deeper/in the old snow, about 100' wide. Also saw one wind slab on a small slope north of Long Lake. 14-16" deep, 20' wide, and within the fresh wind slab. "Full Snow Observation Report
We rode up Taylor Fork around Skyline Ridge towards Cabin Creek. We found 12" of new snow had fallen over the last 24 hours. With poor visibility, we were unable to see any recent avalanche activity except for a small recent avalanche that happened near Beaver Slide. This was right next to a much larger slide that Doug and Ian had seen on 02/14/2024. While riding back we had a good view of the backside of Skyline Ridge above us and again saw no recent avalanche activity. However, many slopes had been stripped by recent winds. Strong winds and a foot of new snow that fell onto a weak snowpack kept us off of and out from underneath steep slopes, and recent snow made for pleasant riding conditions.Full Snow Observation Report
From IG message: “These are on the ridge between Miller Mtn and Sunset Peak on North aspect. All of the North facing ridge of Miller Creek up to Miller Mountain had similar slides too. The crowns filled back in overnight… The North facing ridge on Sheep Mtn slid as well, not sure on the trigger but a rider from another group send the following image of the Sheep slide“Full Snow Observation Report
Toured up the west side of Woody via Central Park approach. Moderate to high wind gusts at the ridge line. Skied a couple laps in variable conditions on Sub bowl and then returned to the West aspect for a lap down South Central .
Traversed into the tube at tree-line roughly 9900’ and triggered a small wind slab. Crown was around ~1 foot deep and maybe 40 feet wide. Possibly stepped down a bit once in the tube and then ran for about 300 feet.
Went up to the prayer flags today. On the ridge about 100yards below the flags I went to the end of the cornice and gave it a stomp. Triggered a windslab that propagated about 50 to the left.
The crown was roughly 1-1.5 ft deep in the most wind loaded area.
Multiple slides have went on this slope already this year, some running a good distance down through the trees.
We rode up the road to Henderson Bench and dug on a northeast facing slope at 9,670'. While digging it was clear how poor the snowpack structure was. It was difficult to dig through a 2 foot thick hard slab, but once through the slab I sunk to the ground through 1.5 feet of weak sugary facets. We had an ECTX. After some extra hits, removing 2/3 of the slab, and a few more hard hits, we got a dramatic collapse and propagation. The facets were F+ in hardness below a P+ hard slab. Although the weak layer was difficult to affect in this spot, finding the right spot on a slope to collapse the weak layer would produce a big avalanche, as shown by a rider triggered slide two days ago on Fisher Mtn.
We also rode up to Daisy Pass. Visibility was good enough to see most slopes, but in flat light. We didn't notice any new avalanches.
Snow was falling lightly (S -1). Overcast skies. Wind was moderate with frequent strong gusts out of the west-southwest, forming drifts along road cuts and convexities.
Full Snow Observation Report
Moving into a trickier snowpack. Tracks on many steep slopes, "stable" test scores, and less obvious signs, but the weak layer is still weak as ever. The snowpit today was a very similar structure to what I saw in the Bridgers the year of the wet slab cycle. A thick pile of depth hoar on the ground with a solid slab above... The depth hopar was worse in 2011-12, but not much. Oh yea, and the surface hoar is on top of the basal facets, just in case.
Despite a lack of activity, considerable feels right. It seems like a wind-loaded slope should break naturally even before this storm really gets going.
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.Full Snow Observation Report
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).Full Snow Observation Report
Danger felt considerable with the stormy conditions and wind-loading. The place definitely got hammered by people last weekend. Many tracks in the Rastas and on the southeast bowl of Scotch Bonnet. Without the current loading it probably would have felt moderate, but we didn't quite make it there or missed it... I expect an easy HIGH on Monday or Tuesday if forecast snowfall plays out.
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 cameraFull Snow Observation Report
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.Full Snow Observation Report