24-25

<p>In the Southern Madison and Southern Gallatin Ranges and the mountains around Cooke City and West Yellowstone, the primary concern is <strong>persistent slab avalanches</strong> failing on deeply buried weak layers. Recently, avalanches 4-6 feet deep have occurred naturally near Cooke City, some triggered remotely from distant flat terrain (<a href="https://www.mtavalanche.com/node/33461"><strong><span>Ian and Alex’s video</span></strong></a>). Yesterday and the day before, slides broke deep within the snowpack south of town (<a href="https://www.mtavalanche.com/node/33520"><strong><span>photos and details, Photos/ details 2</span></strong></a>).</p>

<p>Around West Yellowstone, the snowpack is shallower, with avalanches likely to break 1-3 feet deep in steep terrain. At Bacon Rind, we triggered <em>many</em> whumphing collapses with shooting cracks (<a href="https://www.mtavalanche.com/node/33534"><strong><span>observation and video</span></strong></a>), and at Lionhead, the terrain near our snowpit collapsed with a thunderous rumble (<a href="https://www.mtavalanche.com/node/33529"><strong><span>observation/</spa…; </strong><a href="https://www.youtube.com/watch?v=I6nDBNZli-Y"><strong><span>video</span>…;

<p>Wind-loading on steep slopes exacerbates the persistent slab problem and could be hazardous independently as <strong>wind slab avalanches</strong> (<a href="https://www.mtavalanche.com/node/33511"><strong><span>slide near Two Top</span></strong></a>).</p>

<p>Enjoy great powder turns and ride in low-angle terrain, avoiding slopes steeper than 30 degrees and runout zones.</p>

<p>The danger is CONSIDERABLE.</p>

<p>Strong winds in the Bridger Range are drifting the plentiful new snow, making <strong>wind slab avalanches</strong> likely today. The distribution is irregular and widespread. Today is the second day of heavy wind loading, and slabs are becoming thicker. Seek out slopes sheltered from the wind to find softer turns and safer conditions.</p>

<p>The last two weeks of snow built a thick slab and steadily added weight to weak layers at the bottom of the snowpack. This snowpack structure makes <strong>persistent slab avalanches</strong> possible. (<a href="https://www.mtavalanche.com/node/33442"><span>Playground observation</span></a>).</p>

<p>The avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on all others.</p>

<p>Recent snowfall and wind in the Northern Madison and Northern Gallatin Ranges make human-triggered avalanches possible. <strong>W</strong><strong>ind slab avalanches </strong><span>can</span> break up to several feet deep on slopes with fresh drifts of wind-loaded snow. Larger wind slabs can bury or kill a skier or rider, and shallower slides are dangerous if they drag you into trees, over cliffs, or pile deep in narrow gullies.</p>

<p>Avalanches failing on persistent weak layers deep within the snowpack are possible. These <strong>persistent slab avalanches </strong>are often triggered from shallower areas on a slope, like near rock outcrops or wind-scoured ridges, and propagate to where the snowpack is deeper (<a href="https://www.youtube.com/watch?v=xHr_3Bdtq1o"><span>Blackmore Video</span></a>).</p>

<p><span>Assess the snowpack for instability before considering travel in avalanche terrain. Less steep slopes sheltered from the wind are less likely to slide, and smaller pitches with fewer terrain traps reduce the consequences of an avalanche. Always follow safe travel practices. The avalanche danger is MODERATE on all slopes. </span></p>

<p>Island Park received less snowfall last week but is deeper overall, resulting in a somewhat more stable snowpack. Despite the more stubborn nature, there's a risk of triggering a 3-5-foot-deep <strong>persistent slab avalanche (</strong><a href="https://www.mtavalanche.com/node/33433"><strong><span>video</span></str…;). Getting caught by an avalanche of this magnitude is likely fatal.</p>

<p>The most recent slides reported from the Island Park area were <strong>wind slab avalanches </strong>in the Mount Jefferson Bowl (<a href="https://mtavalanche.com/node/33400"><span>info and photos</span></a>). Slope loaded by wind-drifted snow makes wind slabs, and large persistent slab avalanches more likely.</p>

<p>Reduce the risk and impact of dangerous avalanches by following safe travel practices and choosing smaller, less steep slopes sheltered from wind-loading with clear runouts and minimal terrain traps. Riding on slopes less than 30 degrees steep without overhead hazard largely eliminates your avalanche risk.</p>

<p>Human-triggered avalanches are possible, and the avalanche danger is MODERATE.</p>