22-23

<p>Excepting last Thursday, the mountains around West Yellowstone and Cooke City have received measurable snowfall every day for over a week, with 9-12” in the last two days and moderate to strong winds for the last four. A lot of new snow and strong winds will likely result in avalanches, especially on wind-loaded slopes where recent drifts could break from a few inches to several feet deep.</p>

<p>This has undoubtedly been the case in Cooke City, with many large natural avalanches and four people caught and partially buried since Saturday (<a href="https://www.mtavalanche.com/node/28338"><strong><span>Town Hill - 2 partially buried</span></strong></a>, <a href="https://www.mtavalanche.com/node/28331"><strong><span>Mt. Abundance - partial burial</span></strong></a>, <a href="https://www.mtavalanche.com/images/23/skier-triggered-slide-near-round-… Lake - partial burial</span></strong></a>). Browse through the <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>Avalanche Activity Log</span></strong></a> on our website to see a complete list of recent activity. Take note of the great <a href="https://www.youtube.com/watch?v=8r-m6BAhr7E"><strong><span>video</span>…; a group of riders captured of a natural avalanche occurring near Pilot Creek on Friday (<a href="https://www.mtavalanche.com/node/28363"><strong><span>additional details</span></strong></a>). Yesterday, Alex and I rode north of Cooke City and described our concerns highlighting wind-loaded slopes (<a href="https://www.youtube.com/watch?v=zg_5u0AZfNo&amp;list=PLXu5151nmAvTi1DBS…;

<p>We have not received an equivalent number of reports from the Lionhead area, but we know that recent snow and wind conditions have been similar, a rider was partially buried on Thursday (<a href="https://www.mtavalanche.com/node/28354"><strong><span>details</span></s…;) and a second group submitted a <a href="https://www.mtavalanche.com/images/23/avalanches-wind-loaded-slopes-lio…; of a recent avalanche on a wind-loaded slope.</p>

<p>Avoid steep, wind-loaded slopes where triggering an avalanche is likely. Evaluate the snowpack for instabilities within or underneath recent snow before considering riding or skiing non-wind-loaded slopes. The avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on other slopes.</p>

<p>In the Gallatin, Madison and Bridger Ranges, 2-11” of snow since Saturday favored the areas further south. Slides breaking a few inches to 2 feet deep within drifts of the most recent snow are the most likely scenario today. Yesterday, the USFS snow rangers reported a small avalanche on a wind-loaded slope at Buck Ridge (<a href="https://www.mtavalanche.com/node/28368"><strong><span>photo and details</span></strong></a>). On Saturday, skiers in the Southern Gallatin Range intentionally triggered a small avalanche on a wind-loaded slope below a cornice (<a href="https://www.youtube.com/watch?v=fiXHzeIBNHI"><strong><span>video</span>…;). Last Friday, a rider triggered a small avalanche at Buck Ridge (<a href="https://www.mtavalanche.com/node/28293"><strong><span>photo and details</span></strong></a>), a large cornice collapsed in Bear Basin (<a href="https://www.mtavalanche.com/images/23/natural-cornice-collapse-beehive"… and details</span></strong></a>), and large natural avalanches occurred on <a href="https://www.mtavalanche.com/node/28360"><strong><span>Mount Bole</span></strong></a>, <a href="https://www.mtavalanche.com/images/23/large-natural-wind-slab-mt-blackm… Blackmore</span></strong></a> and <a href="https://www.mtavalanche.com/node/28325"><strong><span>Fan Mountain</span></strong></a>. While less likely, larger avalanches similar to those in Hyalite and near Big Sky that break under the 2-4’ of snow from the last week are possible.</p>

<p>Identify and rule out wind-loaded slopes by noting, for example, active drifting or areas below or next to cornices. On non-wind-loaded slopes, test for instability with a quick snowpit before considering riding or skiing steeper terrain. Today, human-triggered avalanches are possible, and the danger is MODERATE.</p>

<p><span>Please share avalanche, snowpack or weather observations via our<a href="https://www.mtavalanche.com/node/add/snow_obs"><span&gt; </span></a><a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;, email (<strong>mtavalanche@gmail.com</strong>), phone (406-587-6984), or Instagram (#gnfacobs). <span><span>&nbsp;</span></span><span>&nbsp;</span></span></p>

<p><span>The Centennial Range received 10-14” of snow in the last 48 hours. Moderate to strong winds are transporting this snow into drifts on wind-loaded slopes where human-triggered avalanches are likely and natural avalanches are possible. Avoid steep, wind-loaded slopes. Evaluate the snowpack for instabilities within or underneath recent snow before considering travel on non-wind-loaded slopes.</span></p>