23-24

<p>Yesterday, lingering cloud cover in the morning kept wet snow avalanches mostly at bay for an extra day. Today will be 5-10 degrees warmer, and direct sun will bake slopes, increasing the danger of wet snow avalanches. These will generally slide as loose snow that starts at a point and fan out as they entrain more snow. While small, these slides have the consistency of wet concrete and can quickly sweep a skier or rider off their feet, pushing them toward terrain trap obstacles such as trees, cliffs and gullies. Less likely are larger wet slab avalanches that can break widely across slopes like this avalanche on the Fin in Cooke City one week ago (<a href="https://www.mtavalanche.com/images/24/fin-cooke-city"><strong><span>pho…;). Recognize increasing danger as the upper 6 inches of the snowpack becomes wet and slushy or you observe rollerballs and small wet snow avalanches. Move to cooler aspects or return to the trailhead before conditions deteriorate.</p>

<p>At upper elevations and cooler aspects where the snow remains powdery, dry slab avalanches are the primary concern, especially on slopes loaded by wind-drifted snow. While these are becoming less likely as we move away from the last snowstorm (<a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a>, <a href="https://youtu.be/iO3EWqb0oqg?feature=shared"><strong><span>Ramp video</span></strong></a>, <a href="https://youtu.be/Fjo1jg8p49M?feature=shared"><strong><span>Throne video</span></strong></a>), dig down through the recent snow, test for instability above the thick melt-freeze crust, and watch for signs of instability, such as cracking at the snowpack surface. Retreat to lower-angle slopes and non-wind-loaded terrain if you observe signs of instability.</p>

<p>Skiers south of Cooke City dug a snowpit to the ground in a shallower area and used an extended column test to investigate the weak faceted snow that continues to make up the foundation of our snowpack. The group was surprised when the test propagated, indicating continued basal instability (<a href="https://www.mtavalanche.com/node/31802"><strong><span>observation</span…;). While avalanches failing near the base of the snowpack have become much less likely, the potential remains, especially on slopes that remained cooler during this winter’s warm-ups.</p>

<p>Human-triggered, dry snow avalanches are possible, and the danger is MODERATE. Wet snow avalanches will become likely as the day warms, and the danger will rise to CONSIDERABLE.</p>

<p>The sun will break out from behind the clouds today, and the danger of wet snow avalanches will rise as the snow from recent storms starts sliding on the underlying crust. The size and frequency of these avalanches depend on how much snow fell during the last storm (Over 2 feet in the Bridger Range, 12” around Big Sky and 4-7” everywhere else), how warm the temperatures get, whether lingering clouds shade slopes and if wind cools the snow surface. Though there is uncertainty about the timing and extent of wet snow avalanches today, recognizing the signs of increasing danger is relatively simple. A wet snow surface, cinnamon roll-like snowballs shedding from steep rocky areas and small natural slides indicate that the danger is increasing. Have a safe exit plan, as conditions can change quickly. Shift to cooler aspects or head home as this transition occurs.</p>

<p>Dry slab activity within the new and wind-drifted snow has decreased since this weekend (<a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a>). However, dry slab avalanches within the recent storm snow are the primary concern before the warm-up and throughout the day at high elevations and shady north-facing slopes. Our recent videos from <a href="https://youtu.be/iO3EWqb0oqg?feature=shared"><strong><span>The Ramp</span></strong></a> and <a href="https://youtu.be/Fjo1jg8p49M?feature=shared"><strong><span>The Throne</span></strong></a> demonstrate digging down until you hit the thick upper ice crust to test for instability in the top few feet of the snowpack before committing to avalanche terrain. Selecting non-wind-loaded terrain is a good way to reduce the risk of triggering a slide.</p>

<p>While a low-probability event, the structure to produce very large avalanches remains present, especially on steep high-elevation slopes and those that remained cool through the recent warm-ups. If seeking this type of terrain, recognize the residual risk of triggering an unsurvivable avalanche and follow safe travel protocols to limit the number of people who might get caught. Slopes that went through recent melt-freeze cycles or less steep, small slopes are safer.</p>

<p>The danger is rated MODERATE and will rise to CONSIDERABLE for wet snow avalanches.</p>

<p><span><span><span><span><span><span>The forecasted clouds and wind will keep the </span></span></span></span></span></span><span><span><span><span><span><u><span><span>wet snow</span></span></u></span></span></span></span></span><span><span><span><span><span><span> avalanche danger at bay for one more day. Although I do not expect sun today, </span></span></span></span></span></span><span><span><span><strong><span><span>if </span></span></strong></span></span></span><span><span><span><span><span><span>it shines, the snow surface will melt quickly and avalanche danger will rise. Stay out of avalanche terrain once you start seeing roller balls or start sinking into wet snow.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The </span></span></span></span></span></span><span><span><span><span><span><u><span><span>dry snow</span></span></u></span></span></span></span></span><span><span><span><span><span><span> avalanche danger is a larger concern, especially on wind-loaded slopes. Over 2 feet of snow fell in the Bridger Range over the weekend with 12” around Big Sky and 4-7” everywhere else. On Sunday, skiers triggered </span></span></span></span></span></span><a href="https://www.mtavalanche.com/avalanche-activity"><span><span><span><stro… avalanches in the Bridger Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> in the new snow. Both Alex and Dave made videos of the instability to look out for </span></span></span></span></span></span><a href="https://youtu.be/iO3EWqb0oqg?feature=shared"><span><span><span><strong>… Ramp (video)</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://youtu.be/Fjo1jg8p49M?feature=shared"><span><span><span><strong>… Throne (video)</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>. This activity has subsided, but the current wind will keep the possibility of triggering slides alive. Wind is loading slopes at many elevations so be careful in gullies and near ridgelines where drifts can be thick. This new snow is sitting on a hard ice crust in many areas which may help avalanches propagate wide.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Deeper in the snowpack near the ground is a layer of facets that blanket our forecast area. This layer is weak and could avalanche, especially on higher elevation slopes that did not experience melting last week. We consider this risk low probability, high consequence. If getting up high is your jam today, then dig, assess and be aware of the possibility of a large avalanche.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The danger is rated MODERATE throughout our forecast area.</span></span></span></span></span></span></p>