24-25

Falling Cornices

Date
Activity
Skiing

Pictures of two cornice triggered avalanches way up the South Cottonwood drainage that was viewed from Alex Lowe. Looks to be in the recent days, around 9,000 feet North facing.

Also a massive cornice that had cracked and was slowly making its way towards falling down. Cornice was around 50 feet long, and largely overhanging. On the standard ascent of the East Ridge of Alex Lowe, the skin track usually travels below this cornice while ascending to the ridge.

Region
Northern Gallatin
Location (from list)
Alex Lowe Peak
Observer Name
Spencer Lipsteuer

Wet Loose Pioneer Mountain

Date
Activity
Skiing

Natural point release avalanche observed from the YC. Occurred out of bounds on the South side of Pioneer Mountain. 

Region
Northern Madison
Observer Name
YC Ski Patrol

Still Wary of Persistent Weak Layers

Date
Activity
Snowmobiling

Another day of warm temps and clear skies allowed us to cover a lot of ground in the Southern Madisons. We rode into the Taylor Fork, up to the weather station, to the top of Carrot Basin, through Sage Basin, up and over into Cabin Creek, and all the way up to the head of Red Canyon.

We spotted a few old avalanches. One in Cabin Creek that was triggered two days ago by snowmobilers on a N facing aspect. At the top of Carrot Basin, we saw a small avalanche (R1-D1) on a N aspect that likely broke yesterday on buried weak layers. We also spotted one cornice-fall triggered (R2-D2) avalanche that broke earlier this week in Sage Basin and then an older wind slab in Sunlight Basin. 

We dug a snowpit in Sunight Basin right next to where Alex and I dug last week. At that site on 2/21, we triggered whumpfing, shooting cracks and got propagation in our snowpit. Today we did not experience any of those signs of instability. Our snowpit showed poor structure with buried surface hoar and facets but yielded ECTN's on that weak layer

There were a handful of small wet-loose avalanches on solar aspects that we noted throughout the day. While northerly aspects stayed cold, solar aspects became wet a couple inches down. 

Despite no remarkable new avalanche activity and the stubborn reactivity in our snowpit, we remain wary of mid-elevation slopes steeper than 30 degrees. Over the last 12 days, we have received reports nearly every day of avalanches breaking on persistent weak layers buried 2-3' deep. Recent nearby avalanche activity in Teepee Basin and Lionhead is evidence that these weak layers should not be trusted quite yet. 

The travel advice remains tricky, but you have a few options:

1. Before committing to steep slopes, dig down 2-3' and assess for layers of buried surface hoar and facets. Make observations as you step off your snowmobile or skis or board - are you staying on the surface or sinking all the way to the ground? 

2. If you are choosing to ride steeper slopes, pick ones with less consequential terrain features like trees, cliffs or gullies.

3. The ol' reliable option: stick to riding slopes less than 30 degrees. 

 

Region
Southern Madison
Location (from list)
Taylor Fork
Observer Name
H Darby

Natural Wet Loose seen on South Texas Shoulder & in Hourglass

Date

Observed multiple wet loose slides naturally triggering and running on south facing slopes beyond bradleys and on the south facing aspects of hourglass chute.

Region
Bridger Range
Location (from list)
Hourglass Chute
Observer Name
Tyler McGarry

ECTP 22 on the Fin

Date
Activity
Skiing

Snowpit attached from Mt. Republic today.  East aspect, 10,000'.

HS 165, ECTP22 at 65.  

No collapsing, no cracking, no avalanche activity to report.  

40 deg F at Fisher Creek SNOTEL today (9100').

 

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
B. Fredlund

Beehive Windslab Avalanche

Date
Activity
Snowboarding

Kicked off a wind slab avalanche 25ft wide on the west ridge of beehive basin. The wind slab was around 8-10ft deep and the debris slid almost to the flat a few hundred feet down the slope. The slide occurred around 9100ft on the east aspect. Neither me nor my partner were carried or caught in the slide. 

 

The windslab that broke off was about 8-10 feet tall. It was mostly a huge section of a cornice that broke and the slope it fell down onto seemed to propagate a few inches down as well. The majority of the debris was from the cornice.

Region
Northern Madison
Location (from list)
Beehive Basin
Observer Name
Reed Lando

GNFAC Avalanche Forecast for Sat Mar 1, 2025

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Triggering a big </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> that breaks on the weak layers that formed in late January is the main concern today. Yesterday in the Lionhead area, Mark and Alex saw two Persistent Slab avalanches that were triggered by snowmobilers during the day (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34421"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=TWCNOrvNvLk&amp;embeds_referring_euri=h…;). One of these slides broke up to 5 ft deep (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/tracks-going"><span><span><span><…;). This is just the latest in a long string of avalanches on these weak layers over the last 10 days, including multiple close calls (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34413"><span><span><span><span><span><… in Cabin Creek</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34368"><span><span><span><span><span><… in Cooke</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34341"><span><span><span><span><span><… in Tepee Basin</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34367"><span><span><span><span><span><… in Cooke</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34301"><span><span><span><span><span><… in Tepee Basin</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34327"><span><span><span><span><span><… in Taylor Fork</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=tAiSHSEDJhY"><span><span><span><span><s… last Wednesday</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Yesterday’s slides clearly show that these weak layers remain reactive. Stay alert even if you’re not riding up near ridgelines. Many of these slides have broken on mid-elevation slopes sheltered from the wind.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>If you want to ride steep slopes today, take the time to do your homework. Dig down below the early February dust layer to look for weak layers and test the snowpack (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=q0IGs0dKpQU"><span><span><span><span><s…’s video shows how to do this</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>). Make sure you’re riding one at a time on steep slopes and have a partner watching from a safe spot.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>With temperatures a bit warmer this morning and forecasted to rise a bit higher than yesterday, watch out for triggering Wet Loose avalanches on sunny slopes this afternoon.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is MODERATE.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>This morning, after a solid overnight refreeze, avalanche conditions are generally safe and you’re unlikely to trigger a slide. The places where you could still trigger a wind slab are becoming fewer and fewer after days of warm temperatures.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>As the day warms up and the snow surface starts to melt, </span></span></span></span></span></span><span><span><span><strong><span><span>Wet Loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> will become a concern. With temperatures starting around freezing and forecast to rise 5 degrees warmer than yesterday (and maybe be the warmest so far this season) these could be a real problem today that deserve respect and consideration.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Wet Loose slides could start beneath your feet or sled, or as start as natural point releases, especially where there are exposed rocks above steep slopes. Look out for wet snow at low elevations and on sunny slopes, especially later in the afternoon when slopes have been baking in the sun all day (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34408"><span><span><span><span><span><… Creek road photo</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>). Be heads up if there are more than a couple inches of wet snow at the surface.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The potential for cornices breaking off is also worth considering before travelling above or below them (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34402"><span><span><span><span><span><… observation</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is LOW first thing this morning and will quickly rise to MODERATE as the day heats up.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar