24-25

<p><span><span><span><span><span><span>Today a person can trigger large </span></span></span></span></span></span><span><span><span><strong><span><span>persistent slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>that break on weak layers buried in the middle of the snowpack or near the ground. These persistent slab avalanches have become less likely since snowfall and strong winds ended late Wednesday, but the potential size and consequences remain large.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>During the first half of this week strong winds drifted new snow into thick, heavy slabs (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=w-aXzlPHrYA"><span><span><span><strong>… video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). On Wednesday there were multiple large natural avalanches near Cooke City (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=zCdhitUHk1o"><span><span><span><strong>…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/large-persistent-slab-avalanche-h… photo</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/images/24/persistent-slab-avalanche-fisher"… photo</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), and an avalanche on Saddle Peak broke 1-3 feet deep (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32548"><span><span><span><strong><span…;). On Tuesday Ian triggered an avalanche remotely (from lower angle terrain nearby) on Buck Ridge near Big Sky (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32497"><span><span><span><strong><span…;), and on Friday a skier had a large collapse in the Bridger Range (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32582"><span><span><span><strong><span…;).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Choose small, simple, non-wind-loaded slopes with clean runouts free of hazards like rocks, trees or cliffs. If you have any doubts about snowpack stability avoid slopes steeper than 30 degrees and be cautious of runout zones below.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Yesterday on Buck Ridge a snowmobiler triggered a 12” deep</span></span></span></span></span></span><span><span><span><strong><span><span> </span></span></strong></span></span></span><span><span><span><span><span><span>wind slab avalanche (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32601"><span><span><span><strong><span…;). Strong winds last night might have formed fresh </span></span></span></span></span></span><span><span><span><strong><span><span>wind slabs</span></span></strong></span></span></span><span><span><span><span><span><span>, and a few potentially unstable drifts could remain from earlier in the week. Look for signs of wind-drifted snow and be cautious of wind-loaded slopes, especially where consequences of a slide are higher due to terrain traps.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Carefully and continuously assess the snowpack and terrain for avalanche potential, and travel one person at a time on steep slopes or through runouts. The avalanche danger is MODERATE.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Large </span></span></span></span></span></span><span><span><span><strong><span><span>Persistent Slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>have been breaking on weak layers in the middle of the snowpack and near the ground (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=zCdhitUHk1o"><span><span><span><strong>…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/large-persistent-slab-avalanche-h… photo</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/images/24/persistent-slab-avalanche-fisher"… photo</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). If you get onto a steep slope today, expect to trigger a similar slide. These slides can be triggered from below, so be cautious passing beneath steep slopes as well.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The first big loading event of the season only ended 48 hours ago. Persistent weak layers are widespread - these weak layers (surface hoar and facets) often remain easily triggered for a couple days after a loading event ends and we expect that to be true today.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Human triggered avalanches are likely and the avalanche danger is CONSIDERABLE. Choose slopes sheltered from the wind, less than 30 degrees steep, without steeper slopes above, for good, safe riding today.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Across the rest of our advisory area, triggering, large, dangerous avalanches is still possible, but they have become a bit less likely. The bulk of the last snowfall event had wrapped up by Monday night. High winds on Wednesday drifted lots of snow (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=w-aXzlPHrYA"><span><span><span><span><s… video</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>), but the snowpack has now had a few days break from loading.</span></span></span></span></span></span></p>

<p><span><span><span><strong><span><span>Persistent Slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>remain a serious concern. Weak layers are widespread in the middle of the snowpack and earlier this week we saw avalanches breaking on them. On Tuesday, I triggered a slide from 200 ft away on Buck Ridge (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32497"><span><span><span><strong><span…;). On Wednesday, an avalanche on Saddle Peak broke 1-3 feet deep, and ran 1500 vertical feet (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32548"><span><span><span><strong><span…;). A large collapse yesterday in the Bridger’s reminds us that similar slides remain possible (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/32582"><span><span><span><strong><span…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Minimize potential consequences by choosing smaller slopes with clean runouts if you decide to get into steeper terrain today. Stay alert for signs of instability (cracking, collapsing, or poor test results).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is MODERATE.</span></span></span></span></span></span></p>