24-25

<p><span><span><span><span><span><span>Today, human-triggered </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> can break on weak layers that formed in late January. Recent avalanches of this type have generally been 2-3 feet deep and 50-200’ wide, and two days ago near Lionhead we saw one that broke 5 feet deep on a heavily wind-loaded slope (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34421"><span><span><span><span><span><…;, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=TWCNOrvNvLk&amp;embeds_referring_euri=h…;). This was the latest in a string of persistent slab avalanches that were triggered over the last twelve days. Many of these were close calls with riders narrowly avoiding being caught and some partially buried and dug out by partners. (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34413"><span><span><span><span><span><… in Cabin Creek</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34368"><span><span><span><span><span><… in Cooke</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34341"><span><span><span><span><span><… in Tepee Basin</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34367"><span><span><span><span><span><… in Cooke</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34301"><span><span><span><span><span><… in Tepee Basin</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34327"><span><span><span><span><span><… in Taylor Fork</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=tAiSHSEDJhY"><span><span><span><span><s… last Wednesday</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>Yesterday we rode in the southern Madison Range and saw one recent small persistent slab, multiple cornice triggered large avalanches, and a few wet slides (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34438"><span><span><span><span><span><…;). In our snowpits we saw poor snowpack structure, and the recent string of human-triggered avalanches are clear signs that weak layers can still produce large avalanches.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>In our </span></span></span></span></span></span><a href="https://youtu.be/W_BeKTJQbUc?feature=shared"><span><span><span><span><s… from yesterday</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> GNFAC intern Haylee describes the persistent slab problem and what to do about it: Your best options are either avoid slopes steeper than 30 degrees, or before committing to steep slopes dig down to check for a poor snowpack structure, and choose slopes with minimal consequences like gullies, trees or cliffs. Keep in mind many (not all) recent slides have been on mid-elevation slopes, surrounded by trees and sheltered from the wind.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Also watch out for triggering </span></span></span></span></span></span><span><span><span><strong><span><span>wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> on sunny slopes as the snow surface melts.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is MODERATE around West Yellowstone and Cooke City.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>This morning avalanche conditions are generally safe and slides are unlikely. Danger will rise through the day for wet snow avalanches as above freezing temperatures melt the snow surface. Temperatures are already above freezing in many places this morning. Clear skies overnight probably helped the surface freeze at least a little, but that may change quickly with the warm temperatures and sunshine.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>As the snow surface starts to melt, </span></span></span></span></span></span><span><span><span><strong><span><span>wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> will become a concern (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/wet-loose-pioneer-mountain"><span…;) and </span></span></span></span></span></span><span><span><span><strong><span><span>cornice falls</span></span></strong></span></span></span><span><span><span><span><span><span> could break off ridgelines. If you find more than a couple inches of wet snow at the surface seek lower angle or shadier slopes. Avoid spending time on slopes below cornices and give them a wide berth while traveling along ridgelines. Yesterday skiers in Hyalite noted cornices peeling off the ridgeline and a cornice fall that triggered a wind slab avalanche on the slope below (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34440"><span><span><span><span><span><…;).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The avalanche danger is LOW this morning and will rise to MODERATE as the day heats up.</span></span></span></span></span></span></p>