21-22

<p>Since Sunday, Cooke City received 13” of snow equal to 1.2” of <a href="https://missoulaavalanche.org/2021/01/what-is-swe-snow-water-equivalent… water equivalent</a> (SWE) with reports of&nbsp;double that in some areas. Winds gusting 45 mph are creating thick slabs sensitive to human triggers. Yesterday, skiers south of town saw multiple cracks shoot 30’ in front of their skis and increasingly stiff slabs throughout the day. North of town, I was happy to see weak layers lower in the snowpack are handling the weight of the new snow well while noting that we would avoid wind-loaded slopes where the scales tip toward instability (<a href="https://youtu.be/QOBIciPigDY"><strong>video</strong></a>,<strong&gt; </strong><a href="https://mtavalanche.com/images/21/cracking-drift-scotch-bonnet"><strong…;). Avoid drifted slopes where human-triggered avalanches failing beneath the new snow or deeper on buried weak layers are likely. Carefully assess the snowpack and routes of travel on non-wind-loaded terrain where avalanches are possible.</p>

<p>The danger is CONSIDERABLE on wind-loaded slopes and MODERATE on all others.</p>

<p>The Southern Madison and Southern Gallatin Ranges received 6” of snow since Sunday equal to 0.6” of SWE with 0” in the Lionhead area. Last week these ranges received nearly 3 feet of snow that fell on a weak layer of facets near the bottom of the snowpack. Doug explains in his <a href="https://youtu.be/7EEn6f8-4fA"><strong>video</strong></a&gt; from Lionhead yesterday that we have a recipe for avalanches. Last week human and naturally occurring slides broke 1-3’ deep at <a href="https://mtavalanche.com/node/25196"><strong>Lionhead</strong></a&gt;, in the <a href="https://www.youtube.com/watch?v=PPHZEgnv4lM"><strong>Taylor Fork</strong></a> and <a href="https://mtavalanche.com/images/21/avalanche-bacon-rind-photo-15-dec-202… Rind</strong></a>. With ongoing wind-loading and a weak layer of snow in the lower part of the snowpack, it remains possible to trigger a large avalanche. The safest way to manage this hazard is to make conservative terrain choices while we wait for the snowpack to stabilize.</p>

<p>The danger is MODERATE on all slopes.&nbsp;</p>

<p>The Northern Madison and Bridger Ranges got 7” of snow equal to 0.7” of SWE since Sunday with 1” in the Northern Gallatin Range. Expect drifts of unstable snow in unusual locations as strong southwest to northwest winds, gusting up to 75 mph (<a href="https://mtavalanche.com/weather/stations/lone-peak-summit"><strong>Lone Peak Summit</strong></a>), load slopes. In wind-loaded terrain, slides, similar to the human-triggered <a href="https://mtavalanche.com/node/25164"><strong>avalanche in the Bridger Range</strong></a> last week, are possible. Yesterday, the Bridger Bowl Ski Patrol performed full avalanche mitigation routes for the first time, testing the equivalent of a backcountry snowpack. They triggered several avalanches that broke down to weak layers on similarly wind-drifted slopes. Carefully assess the snowpack searching for isolated areas of instability like two groups of skiers in Hyalite this weekend, one of whom reported unstable results and wisely choose to ski lower angle terrain.</p>

<p>The danger is MODERATE on wind-loaded slopes and LOW on all others.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong>website<…;, email (<a href="mailto:mtavalanche@gmail.com"><strong>mtavalanche@gmail.com</strong></a…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>