Snowpack and Avalanche Discussion
<p><span><span><span><span><span><span>Large, dangerous human triggered avalanches are likely today. Don’t let the expiration of yesterday’s avalanche warning for Cooke City lull you into any sort of complacency, conditions remain quite dangerous. Avalanches can be triggered from far away and from the bottom of slopes. Yesterday was quieter, but look to all the remotely triggered avalanches on Thursday for examples of what we’re concerned about (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=74rb5HCvbsE"><span><span><span><strong>… City video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30037"><span><span><span><strong><span… photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30046"><span><span><span><strong><span… Fork photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Recent avalanches are the best clue that you can trigger more avalanches (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=LzkWoa4viY0&t=1s"><span><span><span… Park video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). These slides are being triggered from hundreds of feet away and breaking 1-2 ft deep on weak layers of surface hoar and facets. With these types of weak layers, stability does not improve quickly. Avalanches can be triggered days and even weeks after the last loading event. Winds have been pretty moderate, but particularly watch for slopes where drifting snow has continued to load the weak layers. Continue to avoid slopes steeper than 30 degrees and be skeptical crossing beneath them as well. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is CONSIDERABLE in the mountains around Cooke City, West Yellowstone and Island Park.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Triggering dangerous avalanches, perhaps from a distance, remains very possible. The danger rating came down a step only because these slides are just a little bit less likely than yesterday. Thursday’s remarkably wide avalanche on Buck Ridge (</span></span></span></span></span></span><a href="https://www.youtube.com/watch/IoM5zbOF5E4"><span><span><span><strong><s…;) and slides triggered from 150 ft away in </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30026"><span><span><span><span><span><…; are good examples of the dangerous and surprising avalanches that are possible today. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Wind loaded and wind effected slopes are the most concerning. A skier triggered an avalanche on a windloaded slope just below the ridgeline on the E face of Mt. Blackmore yesterday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30064"><span><span><span><strong><span…;). It broke around 8” deep, 50 ft wide and ran almost all the way to the typical skin track. Skiers near Big Sky and in the Bridger Range noted cracking and collapsing, indications that the weak layers in the snowpack remain ready to avalanche (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/30059"><span><span><span><span><span><… Sky observation</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Continuing to avoid riding on or under slopes steeper than 30 degrees is a reasonable tactic for a low stress day. If you are going to travel in avalanche terrain, be highly alert for signs of instability and doubly wary of any slope where the snow has been affected by the wind. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is MODERATE near Bozeman and Big Sky.</span></span></span></span></span></span></p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.