24-25
Shooting Cracks in Bacon Rind
Date
Activity
Skiing
While doing stability tests on the bottom 100 ft of the Bacon Rind Runout, we observed multiple "whumps" and a 10-12 ft crack about 5" deep on ~20° terrain.
Region
Southern Madison
Location (from list)
Bacon Rind
Observer Name
Atticus M
Unstable Conditions at Lionhead
Date
Activity
Snowmobiling
We rode from Buttermilk past Ski Hill to the lowest portion of Lionhead Ridge, where the cornice line transitions to the wind-loaded rollover. There is a lot of new snow, and while there are still plenty of landmines, the riding is getting pretty good. No collapsing or cracking was observed. We dug on the northeast aspect on this mid/upper elevation slope and found the same persistent weak layer of concern buried 2.5 feet deep (Fist hardness surface hoar and facets). I was surprised by how sensitive this interface seemed given the depth (ECTP13).
We then rode down and around to Denny Creek and up the local route to the lower meadow, where you first break out of the trees. We dug a second pit at the top of the first hill. Same story on this southeast aspect at 7900.' Fist hard facets and surface hoar buried 2.5 feet deep, ECTP13, no cracking or collapsing observed.
I do not trust this snowpack. It is weak, it is failing with relatively small force given its depth, and the problematic snowpack structure seems to exist on every slope I have assessed this season in the Lionhead area. You might not trigger a slide on every steep slope right now, but you wouldn't need to ride many before triggering an avalanche. The structure seems uniform enough that remote-triggered slides are in play.
The CONSIDERABLE danger seems spot on with human-triggered avalanches likely on slopes steeper than 30 degrees. A forecast with continued snowfall will keep this snowpack on edge.
Region
Lionhead Range
Location (from list)
LIONHEAD AREA
Observer Name
Dave Zinn
Storm slab Avalanches near Cooke
Daisy Pass
Cooke City
Code
SS-R3-D2
Elevation
9800
Aspect
W
Latitude
45.05900
Longitude
-109.95600
Notes
On Jan 2, 2025 We rode over Daisy Pass and out to Abundance, then around Fisher and behind Scotch Bonnet, and back to Lulu Road. Visability was marginal with overcast skies and light snowfall in and out through the day. Wind was light to moderate with moderate gusts. Moving some snow from trees and along the surface, stiffening slabs. Snowfall rates picked up this evening.
We saw three avalanches just north of Daisy Pass and one on Henderson Mtn. The one on Henderson was difficult to see the crown, but we could see the debris. Two of the slides north of Daisy were 2-3' deep and 100-150' wide and ran into thick stands of trees, looked like thick soft slabs/drifts of recent snowfall. The other slide was 1-2' deep and 300-500' wide, soft slab of recent snow.
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
R size
3
D size
2
Problem Type
Storm Slab
Slab Thickness
24.0 inches
Vertical Fall
300ft
Slab Width
150.00ft
Images
Attached Videos
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year
On Jan 2, 2025 we saw three avalanches just north of Daisy Pass and one on Henderson Mtn. The one on Henderson was difficult to see the crown, but we could see the debris. Two of the slides north of Daisy were 2-3' deep and 100-150' wide and ran into thick stands of trees, looked like thick soft slabs/drifts of recent snowfall. There were a lot of tracks from previous days nearby, but trigger in unknown. The other slide was 1-2' deep and 300-500' wide, soft slab of recent snow. Photo: GNFAC
Avalanche Details: Storm slab Avalanches near Cooke
Forecast link: GNFAC Avalanche Forecast for Sat Jan 4, 2025
Cooke City, 2025-01-03
Forecast link: GNFAC Avalanche Forecast for Sat Jan 4, 2025
Jan 2, 2025 We dug a pit between Scotch Bonnet and Sheep Mtn. on a sw facing slope at 9,800'. HS was 135cm (4feet). We had ECTP12 and ECTP26, both on a layer at similar height as the surface hoar has been found (1.5-2 feet above the ground). The weak layer was mostly 2-3mm facets w/ small cups and some signs of surface hoar on top of a melt-freeze crust. Photo: GNFAC
Weather and Avalanche Log for Fri Jan 3, 2025
@0400
AVALANCHE WARNING for Cooke City
GNFAC Avalanche Forecast for Fri Jan 3, 2025
Snowpack and Avalanche Discussion
<p><span><span><span><span><span><span>Heavy snowfall overnight and continued heavy snowfall today mean that natural and human triggered avalanches are both likely. Avalanches may break within the new snow or on the weak layers buried 2-4 ft deep (deeper in windloaded areas). Warming temperatures overnight mean the new snow is falling “upside down” (denser over less dense), which makes </span></span></span></span></span></span><span><span><span><strong><span><span>Storm Slab avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> within the new snow especially likely. Avalanches will be bigger and even easier to trigger on windloaded slopes.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Persistent Slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>breaking deeper in the snowpack on the early December weak layers are the wild card that really worry me today. During the last round of snow, there were big natural avalanches on </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33142"><span><span><span><span><span><… Mountain</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33267"><span><span><span><span><span><… Peak</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>. With rapid loading of the weak layers, I expect more of these big slides today. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Be very cautious if you get out today. Stay off and out from under all steep slopes. Low visibility will make it hard to tell how close you’re getting, so give yourself a wide margin. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is HIGH on all slopes.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Steady snowfall over the last ten days has kept the snowpack teetering on the edge. It’s snowing again and you could easily trigger a large </span></span></span></span></span></span><span><span><span><strong><span><span>Persistent Slab avalanche</span></span></strong></span></span></span><span><span><span><span><span><span> on weak layers buried 1-3 ft deep (and deeper in windloaded areas). We continue to get feedback from the snowpack via collapsing, whumpfs, and avalanches (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/snow-observations-list"><span><span><span><… out our observations page</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> to view the latest reports with all these red flags). New snow today will make these easier to trigger.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Winds have generally been light since snowfall began, so there is still plenty of soft snow available to blow around. Yesterday, the Big Sky Ski Patrol found sensitive wind slabs after the winds picked up just a little bit. Be on the lookout for fresh wind drifts where you could trigger a </span></span></span></span></span></span><span><span><span><strong><span><span>Wind Slab avalanche</span></span></strong></span></span></span><span><span><span><span><span><span> today. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Decision making should be pretty simple today - it’s snowing, weak layers are getting loaded, and avalanche conditions are dangerous. There is powder everywhere, so go out and enjoy it on slopes less than 30 degrees steep. The steep slopes will still be there when it stops snowing and conditions stabilize.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is CONSIDERABLE today.</span></span></span></span></span></span></p>
<p> </p>
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Recent Avalanches near Cooke
Date
Activity
Snowmobiling
We rode over Daisy Pass and out to Abundance, then around Fisher and behind Scotch Bonnet, and back to Lulu Road. Visability was marginal with overcast skies and light snowfall in and out through the day. Wind was light to moderate with moderate gusts. Moving some snow from trees and along the surface, stiffening slabs. Snowfall rates picked up this evening.
We saw three avalanches just north of Daisy Pass and one on Henderson Mtn. The one on Henderson was difficult to see the crown, but we could see the debris. Two of the slides north of Daisy were 2-3' deep and 100-150' wide and ran into thick stands of trees, looked like thick soft slabs/drifts of recent snowfall. The other slide was 1-2' deep and 300-500' wide, soft slab of recent snow.
We dug a pit between Scotch Bonnet and Sheep Mtn. on a sw facing slope at 9,800'. HS was 135cm (4feet). We had ECTP12 and ECTP26, both on a layer at similar height as the surface hoar has been found (1.5-2 feet above the ground). The weak layer was mostly 2-3mm facets w/ small cups and some signs of surface hoar on top of a melt-freeze crust.
With a lot of recent new snow and more on the way, plus recent avalanches and poor snow structure, I expect avalanches will continue through the weekend. Choose routes that avoid travel on and below slopes steeper than 30 degrees.
Region
Cooke City
Location (from list)
Daisy Pass
Observer Name
Alex Marienthal