24-25

<p><span><span><span><span><span><span>A person can trigger avalanches 2-4 feet deep, or deeper on some wind-loaded slopes, which break on persistent weak layers near the bottom of the snowpack. You are more likely to trigger these big </span></span></span></span></span></span><span><span><span><strong><span><span>persistent slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>on slopes with snow depths less than 3-4 ft deep. On big slopes where snow depth varies you can trigger one of these slides from a thinner area and it can break wide into a deeper part of the slope. Choose slopes that are non-wind-loaded and with a relatively deep and more uniform snow depth, or stay on slopes less than 30 degrees to keep it simple. Recent avalanches show some of the types of terrain to avoid to minimize triggering a persistent slab avalanche (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33584"><span><span><span><strong><span… Mountain</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33544"><span><span><span><strong><span… Ridge 1</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33528"><span><span><span><strong><span… Ridge 2</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Additionally, </span></span></span></span></span></span><span><span><span><strong><span><span>wind slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>can be triggered where the recent snow has been drifted into soft slabs up to 1-2 feet thick. Assess the snowpack for unstable drifts, assess the terrain for consequences like cliffs, trees and gullies, and remember even a small slide can easily knock you down. Human-triggered avalanches are possible and the avalanche danger is MODERATE near Cooke City, West Yellowstone and in the southern Madison and Gallatin Ranges.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Near Bozeman, Big Sky and Island Park </span></span></span></span></span></span><span><span><span><strong><span><span>wind slab avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> can be triggered where recent snow has been drifted into slabs up to a couple feet thick. Watch for drifting snow off ridgelines (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/saddle-peak-wind-transport"><span…;) and cracking across the snow surface (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/shooting-crack-jefferson-17-jan-2…;) as signs that fresh wind slabs exist. Older drifts of snow that formed over the last week will be more stubborn, but worth watching out for. Note that strong winds last week formed some drifts in less typical locations like lower elevations.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Avalanches breaking on persistent weak layers are unlikely in these parts of our forecast area. However, buried weak layers do exist, so it is worth choosing slopes with a deeper, more uniform snow depth. See our recent observations from </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/33746"><span><span><span><span><span><… Park</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/33742"><span><span><span><span><span><…. Ellis</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.youtube.com/watch?v=63ynwwMOJ4U"><span><span><span><span><s…’s video</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> for more info on this unlikely persistent slab problem.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>In the mountains around Bozeman, Big Sky, and Island Park the avalanche danger is MODERATE on wind-loaded slopes and LOW on other slopes. Assess the snowpack for buried weak layers and unstable drifts before committing to steep slopes.</span></span></span></span></span></span></p>