19-20

<p>Since the New Year the mountains near Cooke City received the most snow in our advisory area (43” of snow equal to 4.3” <u><a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… snow water equivalent</a></u>) which creates dangerous avalanche conditions. A skier or rider can easily trigger an avalanche on wind loaded slopes where moderate wind has drifted the new snow into fresh slabs. On Friday a snowmobiler triggered an avalanche near Daisy Pass and a recent natural avalanche was seen on the ridge of Miller (<u><strong><a href="https://www.mtavalanche.com/images/20/snowmobile-triggered-slide-chimne…;, <u><strong><a href="https://www.mtavalanche.com/images/20/natural-avalanche-miller-mountain…;). These thick slabs can be deadly, and plus-sized avalanches are possible if they break on persistent weak layers deeper in the snowpack. Avoid steep wind loaded slopes and carefully evaluate snowpack and terrain before crossing on or underneath any steep slope. Avalanche danger is CONSIDERABLE on wind loaded slopes and MODERATE on non-wind loaded slopes.</p>

<p>In the Bridger Range and mountains from Big Sky to West Yellowstone it is possible to trigger an avalanche on weak, sugary snow near the ground. On Friday, Dave found this unstable snowpack structure on the Throne in the northern Bridger Range (<u><strong><a href="https://www.youtube.com/watch?v=WUM0Q69fPZE&amp;list=PLXu5151nmAvSbcbVf…;), and last week skiers in Truman Gulch on the west side of the Bridgers found a similarly unstable snowpack (<strong><a href="https://www.mtavalanche.com/images/20/truman-gulch-profile-8-jan">snowp…;). We have consistently found a poor snowpack structure at Buck Ridge, Beehive, Taylor Fork and near West Yellowstone (<strong><a href="https://www.youtube.com/watch?v=QoHpKz6J52s&amp;list=PLXu5151nmAvSbcbVf…;). Last week large avalanches broke deep in the snowpack on these weak layers near Big Sky (<u><strong><a href="https://www.mtavalanche.com/images/20/avalanche-ground-yc">photo</a></s…;, <u><strong><a href="https://www.youtube.com/watch?v=7vDe6LE-nhU&amp;list=PLXu5151nmAvSbcbVf…;). Recent snowfall has been light and not overloaded the snowpack, but weak layers remain under stress and just need the weight of a human to trigger a large avalanche (<u><strong><a href="https://www.youtube.com/watch?v=omt8Tt1rwms&amp;list=PLXu5151nmAvSbcbVf… href="https://www.mtavalanche.com/images/20/hebgan-lake-road-cut-avalanche-ja…;). Addittionally, fresh drifts are possible to trigger and can break deeper and wider on buried weak layers. These fresh drifts are thicker and more likely where recent snowfall was deeper, like near Big Sky and the Bridger Range.</p>

<p>Large avalanche are becoming more difficult to trigger, but their consequences remain deadly. Be careful with terrain choices and snowpack evaluation before riding steep slopes. Avalanche danger is MODERATE.</p>

<p>The northern Gallatin Range received 12-15” of snow over the last week which fell on a generally stable snowpack. This area received minimal snow over the last month, and we have not received reports of avalanches or collapsing on deeper persistent weak layers. Yesterday I toured to Mt. Blackmore in Hyalite and our main avalanche concern was fresh drifts of snow (<strong><a href="https://www.youtube.com/watch?v=Fdgt5Mp8E6s&amp;list=PLXu5151nmAvSbcbVf…;). We saw debris from a couple small wind slabs. Otherwise, we did not see signs of instability and got no unstable test results in multiple snowpits. Avalanches are possible to trigger on wind loaded slopes where danger is MODERATE. Avalanche danger is LOW on non-wind loaded slopes.</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).</p>