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<p>The Lionhead area near West Yellowstone has dangerous avalanche conditions. Large avalanches are easy to trigger on steep slopes, and from adjacent less steep terrain. Avoid steep slopes and terrain below. Two to three feet of heavy snow is sitting over weak, sugary facets. The weight of a rider or skier can easily collapse the heavy slab of snow across entire slopes (<a href="https://youtu.be/taPrFLj52aA"><strong>video</strong></a&gt;). Yesterday, two large snowmobile triggered avalanches were observed (<strong><a href="https://www.mtavalanche.com/images/18/snowmobile-triggered-avalanche-li…;), and on Saturday snowmobilers triggered a large slide from low on the slope (<a href="https://www.mtavalanche.com/images/18/remote-triggered-slide-near-lionh…;). No one was caught in these slides. Last Wednesday, an avalanche claimed the life of a rider in the nearby Centennial Range where there is a similarly unstable snowpack. Today, dangerous avalanche condition exist and the avalanche danger is <strong>CONSIDERABLE</strong>.</p>

<p>The mountains near Cooke City got 2-3 feet of snow equal to 2.7” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a> (SWE) Wednesday through Saturday. This load produced large natural avalanches (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanches-fin">photo</a>…;), mostly on wind loaded slopes (<strong><a href="https://www.mtavalanche.com/images/18/wind-slab-avalanche-near-lulu-pas…;, <strong><a href="https://www.mtavalanche.com/images/18/natural-wind-slab">photo</a></str…;, <strong><a href="https://www.mtavalanche.com/images/18/natural-avalanches-hayden-creek">…;). Similar avalanches are possible to trigger today. Strong northwest wind last night created smaller, fresh wind slabs that are easy to trigger. On non-wind loaded slopes, larger avalanches are possible on weak layers buried 3-4’ deep (<strong><a href="https://www.mtavalanche.com/images/18/mtn-goat-triggered-slide">photo</…;). These are more likely where the snowpack is shallower, 3-5’ deep. Today, avalanche danger is <strong>CONSIDERABLE</strong> on wind loaded slopes and <strong>MODERATE</strong> on non-wind loaded slopes.</p>

<p>Last week the mountains near Big Sky and Bozeman got 2- 3 feet of snow. In the Bridger Range this snow equaled 3.7” SWE, and in the Gallatin and Madison Ranges 1.5-2.5” of SWE. On Saturday, large slabs of new snow avalanched naturally south of Bridger Bowl (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanche-argentina-bowl"…;). Yesterday, we found these instabilities and anticipate they will quickly heal (<strong><a href="https://youtu.be/QMEdLpX2oDs">video</a></strong&gt;). Over the weekend, skiers and climbers in Hyalite observed natural avalanches, and avoided wind loaded slopes (<strong><a href="https://www.mtavalanche.com/images/18/natural-wind-slabs">photo</a&gt;, </strong><a href="https://youtu.be/D_yPQDu0REg"><strong>video</strong></a&gt;). Today, similar wind slabs are possible to trigger.</p>

<p>Avalanches on weak facets 2-4’ deep are possible, but less likely without new snow. This instability is found where the snowpack is relatively shallow, 3-5’ deep. On Friday, skiers in the northern Madison Range remotely triggered a large avalanche on this layer (<a href="https://www.mtavalanche.com/images/18/skier-triggered-slide-dudley-cree…;). Be cautious of lower elevation terrain and slopes with highly variable snow depth. Today, the avalanche danger is <strong>MODERATE</strong> on all slopes.</p>

<p>If you get out and have any avalanche or snowpack observations to share, drop a line via our <a href="https://www.mtavalanche.com/node/add/snow_observation">website</a&gt;, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a&gt;), phone (406-587-6984), or Instagram (#gnfacobs).</p>