Snowpack and Avalanche Discussion
<p>Dangerous avalanche conditions exist in the Southern Madison and Southern Gallatin Ranges and the mountains around Island Park, West Yellowstone and Cooke City due to persistent weak layers buried throughout the lower snowpack. Skiers and riders continue to report many clear signs of instability.</p>
<p>Yesterday in the Lionhead area, a group remotely triggered an avalanche on a small slope from twenty feet away (<a href="https://www.mtavalanche.com/node/29951"><strong><span>photos and details</span></strong></a>), and two groups experienced widespread cracking and collapsing that extended nearly 200 feet in front of their sleds <span>(</span><a href="https://www.mtavalanche.com/node/29961"><strong><span>observation</span…;, </span><a href="https://www.mtavalanche.com/node/29964"><strong><span>observation 2</span></strong></a><span>).</span> One team of riders stated, “<span>We did not venture onto steeper slopes, but it felt like they would slide easily if we did!” A fourth group at Lionhead sent a photo of a recent natural avalanche (</span><a href="https://www.mtavalanche.com/node/29952"><strong><span>Watkins Creek photo</span></strong></a><span>). A group of skiers in Cooke City walked south of town to document the recent </span>avalanche cycle and noted avalanches on many aspects and collapsing and cracking that got “spookier” in higher elevation terrain more exposed to the wind (<a href="https://www.mtavalanche.com/node/29956"><strong><span>photos and details</span></strong></a>).</p>
<p>While yesterday’s reports focus on the Lionhead and Cooke City areas, the snowpack and recent loading patterns are similar in Island Park and the Southern Gallatin and Southern Madison Ranges (<a href="https://www.youtube.com/watch?v=aTnE5gzG1sc"><strong><span>Taylor Fork video</span></strong></a>, <a href="https://youtu.be/_Q_YPhkGuQk"><strong><span>Centennials video</span></strong></a>). Recent <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity</span></strong></a> points to a snowpack in which human-triggered avalanches remain uncharacteristically likely this long after the last loading event.</p>
<p>The danger is rated CONSIDERABLE. Slopes less than 30 degrees in steepness and without steep terrain above are generally safe from avalanches. Careful route-finding, a thorough snowpack assessment and a conservative mindset are essential on and around steeper terrain.</p>
<p>Human-triggered avalanches are possible in the mountains around Bozeman and Big Sky. As I described in my <a href="https://youtu.be/UU09uX5hvGY"><strong><span>video</span></strong></a> from Beehive Basin yesterday, persistent weak layers buried within the snowpack are nearly universal across aspects and elevations. Where these weak layers are capped by a sufficient slab of cohesive snow from wind-loaded drifts or recent storms, they can produce avalanches. As Alex and his partner noted last week on <span>Buck Ridge,</span> loose snow avalanches or sluffs of weak faceted snow are possible on steep slopes and can gouge deep into the season’s snowpack <span>(</span><strong><u><span>video</span></u></strong>).</p>
<p>Avoid the avalanches by seeking out lower-angle terrain or minimize the odds of triggering a slide by selecting terrain sheltered from recent wind loading and testing for instability before considering steeper terrain.</p>
<p>The 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.
Every 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.
