24-25

<p><strong>Wind slab instabilities</strong> are often sensitive to human triggers one day and stubborn the next. However, in the mountains around Bozeman and Big Sky, recent drifts of snow rest on weak layers that will slow their stabilization on some slopes.</p>

<p>Yesterday, skiers saw a natural wind slab avalanche in Hyalite Canyon (<a href="https://www.mtavalanche.com/node/33871"><strong><span>info and photo</span></strong></a>), and Sunday, skiers north of Bridger Bowl triggered an avalanche on a wind-loaded slope that broke a foot deep and twenty feet wide. Others noticed shooting cracks in wind-drifted snow (<a href="https://www.mtavalanche.com/node/33857"><strong><span>observation 1</span></strong></a>, <a href="https://www.mtavalanche.com/node/33851"><strong><span>observation 2</span></strong></a>). Recent avalanche activity and cracking are clear signs of instability. Avoid wind-loaded slopes or assess the upper few feet of the snowpack for instability related to drifted snow sitting on top of weak layers.</p>

<p>Temperatures in the 30s under sunny skies this afternoon may result in <strong>wet loose snow avalanches</strong>. These are most likely on south-facing slopes (SE, S, SW). Shift your travel to cooler, northerly aspects if you notice the snow surface getting wet, pinwheels or wet loose avalanches.</p>

<p><span>Seek out slopes protected from the wind and sun for the best and safest conditions and assess the upper few feet of the snowpack for instability before traveling in steep terrain. The avalanche danger is MODERATE. </span></p>

<p><span><span><span>In Island Park, West Yellowstone, Cooke City, and the Southern Gallatin and Madison Ranges,<strong> </strong>temperatures will climb above freezing under sunny skies. This afternoon, on southerly aspects, <strong>wet loose snow avalanches</strong> will start at a point and entrain snow as they slide. Move to cooler aspects if the snow surface gets wet and gloppy or you observe pinwheels start to come off rocky bands or trees. </span></span></span></p>

<p><span><span><span><em>Dry snow</em> avalanches are unlikely but not impossible (<a href="https://youtube.com/shorts/wYfXLeIfQ38"><strong><span>Lionhead video</span></strong></a><strong>, </strong><a href="https://youtube.com/shorts/zUjqH2ol3u8"><strong><span>Cooke City video</span></strong></a>). Yesterday, Alex and I discussed in our <a href="https://www.youtube.com/shorts/SwBUd5Yon3A"><strong><span>video</span><…; </strong>how people often begin to push into steeper terrain when the danger drops. While this is reasonable during periods of low danger, steep and extreme terrain is also where you may encounter isolated instability. Yesterday, we saw a small avalanche in the Republic Creek drainage that failed when a cornice fell on very steep, rocky terrain (<a href="https://www.mtavalanche.com/images/25/cornice-fall-republic-creek"><str…;). The idea of getting tumbled by a similar slide is concerning at best.</span></span></span></p>

<p><span><span><span>Persistent weak layers still lurk near the base of the snowpack, slides failing on these layers as <strong>persistent slab avalanches</strong> are currently unlikely, but the danger will return with the next snowstorm. Large slides south of Cooke City in the last two weeks demonstrate their potential (<a href="https://www.mtavalanche.com/node/33865"><strong><span>observation</span…;, <a href="https://www.mtavalanche.com/node/33847"><strong><span>photo</span></str…;).</span></span></span></p>

<p><span><span><span>Follow safe travel protocols, remain observant of indicators of isolated instability and shift to more northerly aspects in the afternoon if snow surfaces get wet. </span></span></span></p>

<p><span><span><span>The avalanche danger is rated LOW in the morning and will increase to MODERATE for wet snow danger in the afternoon. </span></span></span></p>