Skiers in Hyalite Canyon observed a small wind slab avalanche just below the ridgeline in Divide Cirque (below cornice on the peak in the center of the photo). Photo: T. Saulnier
Skiers near Bridger Bowl reported a thin snowpack with "a distinct crust at around 21 cm with a loose, semi-sugary layer of snow just above it from 21-27cm above the ground." Photo: H. Darby
Skiers in Beehive Basin observed pin wheels on a south-facing slope that are consistent with this weekend's warm temperatures. Unusual for late November in Montana! Photo: Dorje
Skiers in Beehive Basin observed a small slab avalanche and pin wheels on a south-facing slope. Photo: Dorje
Skiers on Mount Blackmore observed cracking within the freshly wind-loaded snow on a southeast-facing slope just below the ridge
Skiers on Mount Blackmore observed cracking within the freshly wind-loaded snow on a southeast-facing slope just below the ridge (11/24/21). Photo: J Schack
<p>Gusty westerly winds drifted this week’s new snow into cohesive slabs which are ready to avalanche. Yesterday, the Big Sky Resort Ski Patrol triggered wind slab avalanches up to 1 ft deep below alpine ridgelines with explosives during avalanche mitigation work. Steep slopes with fresh drifts of new snow in the backcountry have the same recipe and should be treated with caution. Unfortunately, these drifted areas also have the best coverage for skiing or riding. Don’t get lulled into poor decisions while trying to avoid rocks. If there is enough snow that you’re considering riding the slope on skis or with your snowmobile, there is enough snow to avalanche. Carefully consider and evaluate both the snowpack and the consequences of triggering an avalanche before riding steep slopes. The many rocks, cliffs and trees that are still exposed provide additional hazards that amplify the consequences of even a small slide.</p>
<p>Some slopes hold snow from October and early November with weak layers that can break in deeper avalanches. Any slope that held snow before this last storm should be suspect. Alex found these weak layers near Cooke City last week (<a href="https://youtu.be/oF8q1tMQuh8"><strong><u>video</u></strong></a>) and skiers near Fairy Lake reported similar layers (<a href="https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w…;). Expect to find these weak layers at higher elevations across the advisory area. </p>
<p>The snow that is on the ground now is the foundation for the whole season’s snowpack. We still have limited information on the developing snowpack and would deeply appreciate hearing what you’re finding while you’re out in the mountains (submit observations <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>here<…;).</p>
<p>We are preparing for winter, teaching avalanche classes, and setting up weather stations. If you have avalanche, snowpack or weather observations to share please submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>
Get your avalanche brain ready for the season at one of the many classes listed on our education calendar, and list of upcoming events below. Don’t delay preparing and inspecting your avalanche gear. Get some tips from Dave Zinn in this Pre-Season gear check video.
Big Sky Resort Ski Patrol reported triggering wind slab avalanches up to 1 ft deep below alpine ridgelines using explosives during avalanche mitigation work on 11/25/2021. Some of the slides broke down into older snow.
![https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w…](https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w_/public/snow_obs/2021-11/258745136_938938460310609_5855336614533349288_n.jpg?itok=-4AQHxeA"><strong><u>photo</u></strong></a>){kind=link}