Snowpack and Avalanche Discussion
<p>The combination of heavy snowfall earlier this week (1-2 ft with 1-1.7” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a>), strong winds, and weak layers in the snowpack have created dangerous avalanche conditions. Avalanches can break beneath the new snow (1-2 ft deep), in a wind drift (3-4 ft deep), or on weak layers near the ground. Numerous natural and human triggered avalanches have been reported in the Bridger Range, near Big Sky, and near Cooke City (<a href="https://www.mtavalanche.com/weather/wx-avalanche-log">avalanche log</a>). Snowfall totals, the amount of wind drifting, and the distribution of weak layers varies a bit between the different mountain ranges, but from a practical perspective it makes no difference. Triggering a large avalanche is likely on any steep slope.</p>
<p>Yesterday, Alex went to the Throne in the northern Bridger Range and found just about every <a href="https://avalanche.org/avalanche-tutorial/red-flags/#avalanches">red flag</a> of avalanche danger. He saw a large natural avalanche on Saddle Peak while driving up the highway, had the snowpack collapse under him, got unstable test results, and had strong winds quickly drifting snow over his tracks (<strong><a href="https://www.youtube.com/watch?v=17YyGFhlMpU&list=PLXu5151nmAvSbcbVf…;). He heeded these signs and stuck to slopes less than 30 degrees.</p>
<p>Last weekend, skiers in the Tobacco Root Mountains (outside our advisory area) <a href="https://avalanche.org/avalanche-encyclopedia/remote-trigger/">remotely triggered</a> an avalanche that broke 6 ft deep on the adjacent face while they were on a lower angled ridgeline (<a href="https://www.mtavalanche.com/images/20/remote-triggered-tobacco-root-mtn…;). They had dug three snowpits during their ascent of the ridgeline with no signs of instability. Their first indication of unstable snow was triggering this huge slide. There is no need for complicated snowpack assessments today. There has been lots of new snow (<strong><a href="https://www.youtube.com/watch?v=pStZS8rCbJ0&list=PLXu5151nmAvSbcbVf…;). There are thick fresh wind drifts (<strong><a href="https://www.youtube.com/watch?v=17YyGFhlMpU&list=PLXu5151nmAvSbcbVf…;). And on some slopes this is all stacked onto unstable weak layers (<strong><a href="https://www.youtube.com/watch?v=Ww-vCQEg-wA&list=PLXu5151nmAvSbcbVf…;). Avoid steep slopes to avoid triggering a large avalanche. Human triggered avalanches are likely and the avalanche danger is CONSIDERABLE.</p>
<p>If you get out, please send us your observations no matter how brief. You can fill out an <strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong>, email us (<strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong>), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.
COOKE CITY
Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.
WEST YELLOWSTONE