17-18

<p>Stability will decrease rapidly with heavy snowfall and strong wind this morning. Yesterday morning, Big Sky ski patrol easily triggered widespread 8-12” deep wind slabs that ran full track with a lot of volume. I was on Buck Ridge yesterday and saw light to moderate wind drifting 6-8” of new snow into unstable slabs (<strong><a href="https://youtu.be/ZnWFDXZ444o">video</a></strong&gt;). Skiers near Cooke City noted natural wind slabs the last two days (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanche-cooke-city">pho…;, <strong><a href="https://www.mtavalanche.com/images/18/natural-wind-slabs-0">photo</a></…;), and on Wednesday a skier in Hyalite triggered a potentially dangerous wind slab (<a href="https://www.youtube.com/watch?v=1WzubfwJ6G4&amp;list=PLXu5151nmAvQSYtIf…;). Today, wind slabs will grow larger and are easy to trigger. On non-wind loaded slopes, new snow will easily slide on firm old snow surfaces.</p>

<p>Cold temperatures, cloud cover and wind make wet snow avalanches unlikely this morning. If sun shines this afternoon, wet loose avalanches of new snow are possible (<strong><a href="https://youtu.be/-cvHq-7k_EQ">video</a></strong&gt;). On Thursday, ice climbers in Hyalite witnessed a large wet loose avalanche over a popular climb, which would be a bad place to be caught (<a href="https://www.youtube.com/watch?v=W_mcy_fnF44"><strong>video</strong></a>…;

<p>Cornices along ridgelines are massive and should be kept a far distance from. On Tuesday, a rider in the Centennial Range broke a cornice, fell 600’ and was injured (<strong><a href="https://www.mtavalanche.com/images/18/cornice-fallcentennial-mtns">phot…;). Below the recent snow, the snowpack is mostly stable and deeper slides are not likely.</p>

<p>With rapidly changing stability today the snowpack may seem complex, but your travel plans don’t have to be. Avoid steep, wind loaded slopes and slopes steeper than 35 degrees. Be aware of potential wet loose avalanches in sunny, steep terrain above you. Conservative terrain selection is the best defense against avalanches today.</p>

<p>Today, human triggered avalanches are likely on wind loaded slopes&nbsp;and natural avalanches are possible. Avalanche danger is rated CONSIDERABLE on wind loaded slopes and MODERATE on non-wind loaded 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>

<p>Yesterday, both wet and dry avalanches were observed. Skiers outside of Cooke City saw multiple wind slabs that failed naturally near upper elevation rock bands (<strong><a href="https://www.mtavalanche.com/images/18/natural-avalanche-cooke-city">pho…;). The same group saw wet loose avalanches later that afternoon. A similar set up will exist today with 4-7” of new snow at upper elevations and rain down low.</p>

<p>Winds slabs and dry loose avalanches will be most prominent on steep slopes above 8,000 feet. Watch for areas of wind drifted snow below upper elevation ridgelines and rock bands. Cracking/collapsing and recent avalanches are obvious clues the snow is unstable. Avoiding wind loaded slopes by&nbsp;making conservative terrain choices&nbsp;will be the best defense against trigging slides today.</p>

<p>At mid to low elevations, wet snow avalanches will be a major concern. Rain on snow overnight will create dangerous avalanche conditions on steep slopes below 8,000 feet. Keeping slope angles below 35 degrees and avoiding terrain traps such as creek beds and gullies will be essential for safe riding at mid to low elevations.</p>

<p>Today, the dry snow avalanche danger is rated <strong>CONSIDERABLE</strong> on wind loaded slopes above 8,000 feet and <strong>MODERATE</strong> on non-wind loaded slopes. The wet snow avalanche danger is rated <strong>CONSIDERABLE</strong> on steep slopes at mid to low elevations.</p>

<p>The mountains around Bozeman picked up plenty of moisture out this storm, but most of it fell as rain. The <a href="https://www.mtavalanche.com/weather/bridger/alpine">Alpine weather station</a> at Bridger Bowl is recording .7” of moisture totaling 1” of snow. That is not a good ratio for powder skiers. That means most of the precipitation fell as rain, which will create dangerous wet snow avalanche conditions in the Bridger Range. Similar conditions exist in the northern Gallatin Range.</p>

<p>Shower Falls Snotel site has not dropped below freezing in 48 hours, which means free moving water is impacting the upper layers of the snowpack creating unstable conditions. Yesterday, ice climbers in Hyalite observed a large wet loose avalanche pour over the Scepter, a very popular ice climb (<strong><a href="https://www.youtube.com/watch?v=W_mcy_fnF44">video</a></strong&gt;). Fortunately nobody was on the climb when the slide occurred. Today, I would steer clear of steep-gullied ice climbs and avoid skiing or riding slopes steeper than 35 degrees, primarily in mid to low elevation terrain (<a href="https://www.mtavalanche.com/images/18/natural-wet-loose-avalanche-yello…;).</p>

<p>On the highest peaks around Hyalite, it will be possible to trigger dry snow avalanches on steep, wind loaded slopes. On Wednesday, a skier triggered a pocket of wind drifted snow that could have been dangerous if triggered in high consequence terrain (<a href="https://www.youtube.com/watch?v=1WzubfwJ6G4&amp;list=PLXu5151nmAvQSYtIf…;). If you’re skiing or riding the upper peaks in Hyalite, approach all wind loaded slopes with caution.</p>

<p>Today, dangerous wet snow avalanche conditions exist and the avalanche danger is rated <strong>CONSIDERABLE</strong> on all slopes below 8,000 ft. In alpine terrain where temps have dropped below freezing, the dry snow avalanche danger is rated <strong>MODERATE</strong> on wind loaded slopes and <strong>LOW</strong> on non-wind loaded 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>