17-18

<p>New snow across the advisory area varies from 3-9” deep and equals .2-.3” snow water equivalent (SWE) even where deepest. Strong westerly wind today will drift new snow into slabs up to 2’ thick that are possible to trigger (<strong><a href="https://youtu.be/aqz9MPBYfyo">video</a></strong&gt;). Be cautious of wind loaded slopes near ridgelines, on steep rollovers, and around cliffs (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanche-airplane-bowl">…;, <strong><a href="https://www.mtavalanche.com/images/18/middle-basin-natural-avalanche">p…;). Look for cracking and collapsing of the new snow as a clear sign to avoid steep, wind loaded slopes. Wind earlier this week drifted snow into dense slabs on top of lower density snow (<a href="https://youtu.be/qrBwGzmoDdA"><strong>video</strong></a&gt;). These can be identified where a ski pole or boot punches through a hard slab into ‘hollow’ snow below. Skiers in Hyalite yesterday found this unstable structure, and avoided steep wind loaded slopes. Cornices along ridgelines are huge and continue to grow (<a href="https://www.mtavalanche.com/images/18/cornices-north-bridger-bowl-bound…;). Keep a far distance from the edge and avoid slopes directly below cornices.</p>

<p>On non-wind loaded slopes the snowpack is generally stable and lacks widespread weak layers. Eric was at Hebgen Lake on Friday and found good overall stability (<a href="https://youtu.be/aqz9MPBYfyo"><strong>video</strong></a&gt;). On some slopes it is possible to find a buried weak layer of facets or surface hoar 2-3’ deep. In Cooke City, Eric found a layer of facets 2’ deep that produced unstable results in stability tests last Tuesday (<a href="https://youtu.be/yu1AnPdOjaI"><strong>video</strong></a&gt;). The new snow is a small amount of weight added to any lingering weak layers, but it is worth digging 3 feet to look for and assess stability before riding steep terrain. Where new snow is deepest, dry loose avalanches are possible and can be harmful if caught above consequential terrain like cliffs.</p>

<p>Today, strong wind and new snow create fresh drifts that are possible to trigger and avalanche danger is <strong>MODERATE</strong>.</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>

<p>The mountains near Cooke City have twice the snow depth as the rest of our advisory area with 11 feet at the Fisher Creek SNOTEL station. Cornices are huge, recently wind loaded slopes have deep drifts, and a weak layer of facets buried 1.5-2’ deep is a concern. Eric found this weak layer on Tuesday and got unstable stability test results (<strong><a href="https://youtu.be/yu1AnPdOjaI">video</a></strong&gt;). This layer should be searched for and assessed before riding steep terrain.</p>

<p>Wind loaded slopes in steep rocky terrain or below ridgelines are most likely slopes to avalanche. Approach wind loaded slopes with caution, and stay a far distance back from large cornices and avoid slopes below. Recent heavy wind-loading and buried weak layers make human triggered avalanches possible today and the avalanche danger is rated <strong>MODERATE</strong>.</p>

<p>Over the past five days, the mountains throughout our advisory area had frigid temperatures with occasional, light precipitation totaling 2-3” of low density snow. The snowpack is generally strong without widespread weak layers, and avalanches today are small or difficult to trigger.</p>

<p>Strong winds yesterday had enough snow to drift into small wind slabs, which will grow larger today if there is more than a couple inches of new snow. Be cautious of these slabs, especially in terrain where consequences are high if caught in a slide. Wind earlier this week drifted snow into dense slabs on top of lower density snow, which Doug found at Bridger on Tuesday (<strong><a href="https://youtu.be/qrBwGzmoDdA">video</a></strong&gt;). These wind slabs could be triggered and should be avoided. They can be identified where a ski pole or hand punches through a harder slab into ‘hollow’ snow below.</p>

<p>Eric was at Hebgen Lake yesterday and found good overall stability. He identified features of concern during low danger, such as high consequence wind loaded slopes, and large cornices (<strong><a href="https://youtu.be/aqz9MPBYfyo">video</a>,</strong&gt; <a href="https://www.mtavalanche.com/images/18/cornices-north-bridger-bowl-bound…;). Be cautious of large cornices and slopes directly below, and isolated wind slabs near ridgelines and in steep, rocky terrain. Otherwise, avalanches are unlikely. Avalanche danger today&nbsp;is rated <strong>LOW</strong>.</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>