21-22

<p>Gusty westerly winds drifted this week’s new snow into cohesive slabs which are ready to avalanche. Yesterday, the Big Sky Resort Ski Patrol triggered wind slab avalanches up to 1 ft deep below alpine ridgelines with explosives during avalanche mitigation work. Steep slopes with fresh drifts of new snow in the backcountry have the same recipe and should be treated with caution. Unfortunately, these drifted areas also have the best coverage for skiing or riding. Don’t get lulled into poor decisions while trying to avoid rocks. If there is enough snow that you’re considering riding the slope on skis or with your snowmobile, there is enough snow to avalanche. Carefully consider and evaluate both the snowpack and the consequences of triggering an avalanche before riding steep slopes. The many rocks, cliffs and trees that are still exposed provide additional hazards that amplify the consequences of even a small slide.</p>

<p>Some slopes hold snow from October and early November with weak layers that can break in deeper avalanches. Any slope that held snow before this last storm should be suspect. Alex found these weak layers near Cooke City last week (<a href="https://youtu.be/oF8q1tMQuh8"><strong><u>video</u></strong></a&gt;) and skiers near Fairy Lake reported similar layers (<a href="https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w…;). Expect to find these weak layers at higher elevations across the advisory area.&nbsp;</p>

<p>The snow that is on the ground now is the foundation for the whole season’s snowpack. We still have limited information on the developing snowpack and would deeply appreciate hearing what you’re finding while you’re out in the mountains (submit observations <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>here<…;).</p>

<p>We are preparing for winter, teaching avalanche classes, and setting up weather stations. If you have avalanche, snowpack or weather observations to share please submit them via our&nbsp;<a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>Where there is enough snow to ski or ride the snowpack has layers and avalanches are possible. Last night’s snowfall of 3-6" was equal to 0.3-0.4"&nbsp;of snow water equivalent (SWE). Moderate northwest wind drifted the new snow into thicker layers which can break and avalanche today. Strong wind tomorrow will continue to grow these layers into thicker slabs. If these wind slabs avalanche, they could be large enough to bury a person, and certainly enough to knock someone over. Small dry loose avalanches of the new snow are also possible. Either of these avalanches are especially dangerous if they knock you over in high consequence terrain, like above cliffs, trees or the many exposed rocks right now.</p>

<p>On slopes that have layers of snow from October and early November avalanches might break 1-2 feet deep on old, weak snow. I saw these weak layers near Cooke City last Friday (<a href="https://youtu.be/oF8q1tMQuh8"><strong>video</strong></a&gt;), and skiers near Fairy Lake reported similar layers over the weekend (<strong><a href="https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w…;). Until proven otherwise, I suspect there are buried weak layers on high elevation slopes throughout our advisory area.</p>

<p>If you go to recreate&nbsp;in&nbsp;the mountains over the next couple days plan to avoid avalanche terrain where there are fresh drifts of snow or if&nbsp;you suspect there are buried weak layers, especially if the terrain has&nbsp;high consequences of being&nbsp;caught in a slide. Choose objectives that give you an opportunity to safely gather data about how this season’s snowpack is looking, and provide yourself time to make clear, informed decisions.</p>

<p>We will issue the next update on Friday morning. We are preparing for winter, teaching avalanche classes, and setting up weather stations. If you have avalanche, snowpack or weather observations to share please submit them via our&nbsp;<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>

<p>New snow that fell by Saturday morning was welcome, but mainly cosmetic. It was not enough to improve the skiing or snowmobiling, but it did cover up the rocks making them easier to hit. West wind was strong at the ridgetops and drifted snow. These wind slabs may avalanche and bury you, but will most likely bounce you over rocks and end your ski season. <a href="http://www.mtavalanche.com/images/21/avalanche-powder-cloud"><strong><u… picture</u></strong></a> of an avalanche powder cloud near Livingston (outside the forecast area) is proof of the lurking danger.</p>

<p>The winter is young and we have limited data which means we need to be extra cautious. <a href="https://www.nrcs.usda.gov/wps/portal/wcc/home/quicklinks/imap#version=1… sites</u></a> are measuring only 10 to 20 inches of snow. At elevations lower than 7,500 feet dirt was seen before the storm, while above this elevation we have a layered snowpack of crusts, a dense icy mass at the ground and weak, sugary snow in between. This week’s weather is favorable to grow large-grained sugary facets, the bane of stability. I’m an optimist at heart, but not with this snowpack. I anticipate it will continue to weaken and then avalanche when snow accumulates.&nbsp;</p>

<p>So what should someone hungry to get out and make turns do? Avoiding wind-loaded slopes is the first step. The second step is to not trust the snowpack. Trust takes time. Alex and his partner were faced with this on Friday when they ski toured south of Cooke City (<a href="https://youtu.be/oF8q1tMQuh8"><strong><u>video</u></strong></a&gt;). They dug <a href="https://www.mtavalanche.com/snowpits"><strong><u>3 snowpits</u></strong></a>, found weak snow that broke in their tests and were very careful to avoid avalanche terrain. As a general rule we go into avalanche terrain, but not right now. If the snowpack is deep enough to ski, then it’s deep enough to have layers of ever weakening snow. Lacking a history of pit data and observations, Alex was rightfully concerned, and you should be too.&nbsp;</p>

<p>Public Safety Message 101: Treat your outing as you would any mid-winter day. Carry a beacon with fresh batteries, a shovel and probe. A helmet is a good idea, especially with rocks lurking, and if you carry an airbag mid-winter, you should carry it now too.&nbsp;</p>

<p>We will issue the next update on Friday morning. We are preparing for winter, teaching avalanche classes, and setting up weather stations. If you have avalanche, snowpack or weather observations to share please submit them via our&nbsp;<a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>