Snowpack and Avalanche Discussion
<p>Human-triggered avalanches are likely in the mountains south of Bozeman through Island Park and Cooke City. Forty-eight-hour snow totals range from 3-6” with 0.3-0.6” of <a href="https://avalanche.org/avalanche-encyclopedia/#snow-water-equivalent-swe… water equivalent</span></a> near Bozeman, Big Sky, West Yellowstone, and Cooke City to one foot with 1.2” of snow water equivalent in the Centennial Mountains in Island Park.</p>
<p>Persistent weak layers deep in the snowpack have resulted in spectacularly large and dangerous avalanches within the last week. Similar slides are possible today. Highlights from the long list available on our <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a> include, in Cooke City, huge slides on Sheep Mountain (<a href="https://www.mtavalanche.com/node/31377"><strong><span>photos</span></st…;), Miller Mountain (<a href="https://www.youtube.com/watch?v=BJGckpdQQpQ&list=PLXu5151nmAvSH326z…;, <a href="https://www.mtavalanche.com/images/24/big-avalanche-north-miller-mtn"><…;), Scotch Bonnet (<a href="https://www.mtavalanche.com/node/31345"><strong><span>details</span></s…;, <a href="https://www.mtavalanche.com/node/31357"><strong><span>details</span></s…;), and Henderson Mountain (<a href="https://www.mtavalanche.com/node/31294"><strong><span>video and details</span></strong></a>). Near Bozeman and Big Sky, a very large avalanche failed naturally on the north side of Mount Blackmore, snapping off mature trees <span>(</span><a href="https://www.mtavalanche.com/node/31432"><strong><span>overview video and photos</span></strong></a><span>)</span>. Three avalanches in Beehive Basin broke 3-5 feet deep (<a href="https://youtu.be/ZaqRmvvNp9c"><strong><span>video</span></strong></a>, <a href="https://www.mtavalanche.com/node/31386"><strong><span>details</span></s…;, <a href="https://www.mtavalanche.com/node/31343"><strong><span>photos</span></st…;), and a rider remotely triggered a large avalanche at Buck Ridge last week (<a href="https://www.mtavalanche.com/node/31305"><strong><span>photo</span></str…;).</p>
<p>Avalanches do not have to break many feet deep to be dangerous. Relatively small avalanches can cause trauma or bury skiers or riders. Slabs of new and wind-drifted snow on steep slopes are likely to avalanche under the weight of a skier or rider. The depth will vary from 6 to 24” depending on the amount of new snow in the area. Doug and I noted what we expect to be short-lived instability below the recent snow in Island Park yesterday (<a href="https://www.youtube.com/watch?v=5Mlxcbf3jrI"><strong><span>video</span>…;
<p>Avoid steep avalanche paths. Select simple, lower-angle terrain without the added risk of terrain traps and follow safe travel protocols. Watch our videos from West Yellowstone and Big Sky discussing terrain selection (<a href="https://www.youtube.com/watch?v=Dn0nFLZlPE8"><strong><span>video</span>…; </strong><a href="https://www.youtube.com/watch?v=ZaqRmvvNp9c"><strong><span>video</span>…;
<p><span>The avalanche danger is CONSIDERABLE. </span></p>
<p>While the snowpack's foundation remains weak, instability is most likely within the new and wind-drifted snow in the Bridger Range. Recent avalanches on Saddle Peak (<a href="https://www.mtavalanche.com/node/31330"><strong><span>details and photos</span></strong></a>) and Naya Nuki (<a href="https://www.mtavalanche.com/node/31418"><strong><span>photos</span></st…;) indicate the types of slides backcountry travelers may encounter today. Relatively small avalanches can push skiers and riders into dangerous obstacles like rocks, trees, and cliffs and can bury us, especially if gullies or trees are present.</p>
<p>Avoid avalanche terrain on slopes where you note signs of instability, including unstable test results, shooting cracks, or signs of recent wind-loading. Choose to recreate on simple, low-consequence terrain and slopes sheltered from the wind. Rescue gear and safe travel protocols with a partner minimize the consequences of mistakes.</p>
<p>Human-triggered avalanches are possible, and the avalanche danger is rated MODERATE.</p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Next weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.