17-18

<p>If you manage to get into the backcountry around Cooke City today, there will be plenty of avalanche hazard to deal with. Nearly two weeks of consistent snowfall, combined with recent strong winds, is creating very dangerous avalanche conditions. Yesterday, Doug and Alex avoided all avalanche terrain and runout zones while riding north of town (<strong><a href="https://www.youtube.com/watch?v=6WwB3XBH5k8&amp;list=PLXu5151nmAvQSYtIf…;

<p>Our biggest issue is new snow and wind loading that will&nbsp;add stress to the snowpack. Avalanches failing in the new snow or on weak layers deeper in the pack are both a concern (<a href="https://www.mtavalanche.com/images/18/east-woody-ridge-avalanche"><stro…;). There is potential for large and destructive avalanches to hit low angle terrain and/or valley bottoms, so be extra cautious when traveling underneath steeper slopes. Avoiding all avalanche terrain is recommended today as the snowpack works overtime to adjust.</p>

<p>Today, very dangerous avalanche conditions exist and the avalanche danger is rated <strong>HIGH</strong> on all slopes.</p>

<p>The main avalanche concern in the mountains around Bozeman, Big Sky and West Yellowstone is wind loading. Strong westerly winds have loaded slopes below ridgelines and cross loaded terrain features (<a href="https://youtu.be/UeRbanc6b3c"><strong>video</strong></a&gt;). Yesterday, a skier up Hyalite in the northern Gallatin Range observed small natural avalanches in wind loaded terrain (<strong><a href="https://www.mtavalanche.com/images/18/small-natural-avalanches-hyalite"…;). Today, I don’t expect wind slabs to be hair trigger, but they could fail under the weight of a skier or rider. In addition to wind slabs, cornices have grown significantly over the past week. These large chunks of snow will be under a lot of stress from recent loading so give them space both on and below ridgelines.</p>

<p>A secondary problem is a layer of buried surface hoar. This layer exists mainly in the mountains south of Big Sky and near West Yellowstone. On Wednesday, I found this layer on a sheltered, northwest facing slope in the Taylor Fork. It consistently produced unstable results in my stability tests (<a href="https://www.youtube.com/watch?v=CFzhlPk5DZw&amp;list=PLXu5151nmAvQSYtIf…;, <a href="https://youtu.be/2mj4jkCkEpc"><strong>video</strong></a><strong>,</stro…; <strong><a href="https://www.mtavalanche.com/images/18/buried-surface-hoar-taylor-fork">…;). This layer&nbsp;has not produced widespread instability and is getting stronger, however, it’s something to look for&nbsp;when skiing or riding in the southern mountains.</p>

<p>Today, human triggered avalanches are possible and the avalanche danger is rated <strong>MODERATE</strong>. Evaluate snow and terrain carefully before committing to steeper 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>