19-20

<p>Yesterday two deep avalanches were triggered by snowmobilers, one near Big Sky (<strong><a href="https://www.mtavalanche.com/node/21678">details</a></strong&gt;) and one in the Centennials (<strong><a href="https://www.mtavalanche.com/images/20/snowmobile-triggered-near-reas-pe…;). A skier north of Bridger was surprised by a smaller, but big enough avalanche (<strong><a href="https://www.mtavalanche.com/node/21672">details</a></strong&gt;). This was similar to a snowmobile triggered slide in Taylor Fork on Saturday (<u><strong><a href="https://www.mtavalanche.com/images/20/snowmobile-triggered-slide-taylor…;). Many recent human triggered avalanches were very big, measuring up to 7 to 15 feet deep. They would kill you if you ended up on the wrong side, luckily nobody has.</p>

<p>Over the weekend there were seven avalanches triggered by skiers and snowmobilers, six were unexpected or “close calls” (<strong><a href="https://www.mtavalanche.com/avalanche-incidents">avalanche log</a></strong>). In addition, we saw natural avalanches in the Bridger Range (<u><strong><a href="https://www.mtavalanche.com/images/20/natural-cornice-triggered-deep-sl…;) and got reports of collapsing from Taylor Fork and the west side of the Bridgers (<strong><a href="https://www.mtavalanche.com/node/21683">details</a></strong&gt;). Yesterday at Lionhead, Dave and I saw a large natural cornice triggered avalanche that broke after a few inches of new snow fell yesterday morning (<strong><a href="https://www.youtube.com/watch?v=Yh3lacqFTaQ&amp;list=PLXu5151nmAvSbcbVf…;, <strong><a href="https://www.mtavalanche.com/images/20/lionhead-ridge-avalanche-2">photo…;).</p>

<p>Avoid heavily wind loaded slopes. These are where you can trigger a large avalanche. In Doug’s <strong><a href="https://www.youtube.com/watch?v=VXVEIqSWvdY&amp;list=PLXu5151nmAvSbcbVf… from the crown</a></strong> of a recent snowmobiler triggered slide near Cooke City he explains how triggering a huge avalanche is possible on these slopes, where snow depth varies from inches to several feet.</p>

<p>Buried persistent weak layers have been steadily loaded by snow and wind since the start of 2020. Large avalanches are getting more difficult to trigger with less snow the last few days, but recent activity is a warning that weak layers are not stable. Dave and I discussed this “scary moderate danger” in this&nbsp;<strong><a href="https://www.youtube.com/watch?v=TBygi0dYfQY&amp;list=PLXu5151nmAvSbcbVf… during our drive yesterday. If you plan to cross or ride on steep slopes carefully assess the snowpack for buried weak layers or fresh wind slabs. Large avalanches are possible to trigger with severe consequences and avalanche danger is MODERATE.</p>

<p>In Hyalite the snowpack was relatively stable while little snow fell through December. A few storms the last couple weeks activated buried weak layers on wind loaded slopes. On Saturday there were three skier triggered avalanches reported from the northern Gallatin Range (<u><strong><a href="https://www.mtavalanche.com/node/21638">details</a></strong></u&gt;, <u><strong><a href="https://www.mtavalanche.com/node/21655">details</a></strong></u&gt;). All broke on wind loaded slopes and appear to have propagated on weak, sugary snow a few feet deep. One was up to 7 feet deep (<u><strong><a href="https://www.mtavalanche.com/node/21650">details</a></strong></u&gt;). Avalanches are possible to trigger on wind loaded slopes where danger is MODERATE. On non-wind loaded slopes avalanches are less likely and danger is LOW.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an&nbsp;<u><strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong></u>, email us (<u><strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong></u&gt;), leave a VM at 406-587-6984, or Instagram (#gnfacobs). Ride safe and have fun.</p>