23-24

<p>Very dangerous avalanche conditions exist in the mountains around Cooke City, where storm totals add up to 19” of snow, equal to 1.9” of <a href="https://avalanche.org/avalanche-encyclopedia/#snow-water-equivalent-swe… water equivalent</span></a> (SWE) since Saturday, and in the Southern Madison and Southern Gallatin Ranges, where 10” of heavy snow equal to 1.1” SWE fell in the last 24 hours. New and wind-drifted snow are overloading a snowpack that Alex described as one of the weakest he has ever seen in his recent <a href="https://www.youtube.com/watch?v=WTcr7DstJ9Y"><strong><span>video</span>…; from Cooke City.</p>

<p>Natural and human-triggered avalanches breaking 2-4 feet deep and failing widely on persistent weak layers are likely. Recent avalanche activity on Miller Ridge (<a href="https://www.mtavalanche.com/node/31037"><strong><span>photo and details</span></strong></a>), a rider-triggered close call on Fisher Mountain (<a href="https://www.mtavalanche.com/node/30998"><strong><span>photos and details</span></strong></a>), and a skier-triggered avalanche on Woody Ridge (<a href="https://www.mtavalanche.com/node/31027"><strong><span>photos and details</span></strong></a>) provide insight into the spectrum of avalanches one might encounter.</p>

<p>Seek out low-angle terrain (less than 30 degrees) that is away from the bottom of steeper slopes. Avoid all avalanche terrain and avalanche runout zones, and enjoy the new snow.</p>

<p><span>The danger is HIGH on all slopes. </span></p>

<p>Dangerous avalanche conditions exist in the mountains around Bozeman, Big Sky, West Yellowstone and Island Park, where 5-8” of new snow, equal to 0.5-0.8” of SWE, and recently wind-drifted snow are adding stress to persistent weak layers buried 2-4’ deep. Large, human-triggered avalanches are likely.</p>

<p>Cautious route-finding that avoids most avalanche terrain and areas immediately below steep slopes is essential to enjoying a safe day in the new snow. Use an inclinometer, or slope meter, to help minimize your exposure to slopes steeper than 30 degrees (<a href="https://www.youtube.com/watch?v=FwREl1-TIZg"><strong><span>Buck Ridge video</span></strong></a>, <a href="https://www.youtube.com/watch?v=_d5_vlY-bjg&amp;list=PLXu5151nmAvTk1fEF… Rule</span></strong></a>).</p>

<p>Recent avalanche activity is the most telling indicator of potential slides. Before yesterday’s snow, reports of avalanches in Targhee Creek near Lionhead Ridge (<a href="https://www.mtavalanche.com/node/31034"><strong><span>photo and details</span></strong></a>), on Fan Mountain (<a href="https://www.mtavalanche.com/node/31007"><strong><span>details</span></s…;), in Bear Basin (<a href="https://www.mtavalanche.com/node/31029"><strong><span>photo and details</span></strong></a>) and <a href="https://www.mtavalanche.com/node/31009"><strong><span>McAtee Basin</span></strong></a> near Big Sky, on <a href="https://www.mtavalanche.com/node/30935"><strong><span>Bridger Peak</span></strong></a> and <a href="https://www.mtavalanche.com/node/30937"><strong><span>south of Saddle Peak</span></strong></a> in the Bridger Range and in the <a href="https://www.mtavalanche.com/node/30949"><strong><span>Mount Bole Basin</span></strong></a> in the Northern Gallatin Range paint a clear picture of the danger.</p>

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

<p>Very dangerous avalanche conditions exist in the mountains around Cooke City, where 12” of snow, equal to 1.2” of snow water equivalent, fell in the last two days. Strong winds from the southwest are drifting snow and wind-loading slopes. Human-triggered and natural avalanches are likely. From Henderson Mountain, Alex described the snowpack as one of the weakest he has observed and cautioned that avalanches will break 2-4 feet deep and propagate widely across slopes (<a href="https://www.youtube.com/watch?v=WTcr7DstJ9Y"><strong><span>video</span>…;). Avalanches could break more deeply on wind-loaded slopes.</p>

<p>Yesterday, a skier triggered a small avalanche on a wind-loaded slope south of Cooke City that broke one foot deep and slid 300 feet (<a href="https://www.mtavalanche.com/node/31027"><strong><span>photos and details</span></strong></a>). On Friday, a rider was caught and carried in a large avalanche near Lulu Pass and thankfully walked away unharmed (<a href="https://www.mtavalanche.com/node/30998"><strong><span>Cooke City photos</span></strong></a>). Conditions are more unstable today.</p>

<p>Avoid all avalanche terrain (slopes steeper than 30 degrees) and areas immediately below, as backcountry travelers have triggered many avalanches from the bottom of slopes and nearby areas this season.</p>

<p><span>The danger is HIGH in the mountains near Cooke City. </span></p>

<p>Dangerous avalanche conditions exist in the mountains around Bozeman, Big Sky, West Yellowstone and Island Park. Heavy snowfall will begin this morning, and strong winds will continue throughout the day, drifting snow into thick slabs sensitive to human triggers. Persistent weak layers buried 1-4 feet deep are likely to fail under the weight of a skier or rider, resulting in large avalanches that break widely across slopes. As I mentioned in my <a href="https://www.youtube.com/watch?v=FwREl1-TIZg"><strong><span>video</span>…; from Buck Ridge yesterday, dangerous conditions don’t mean you can’t go into the backcountry. However, accurately identifying slopes steep enough to slide and their safer counterparts is an essential skill (<a href="https://www.mtavalanche.com/education"><strong><span>avalanche education and resources</span></strong></a>, <a href="https://www.youtube.com/watch?v=_d5_vlY-bjg&amp;list=PLXu5151nmAvTk1fEF… Rule</span></strong></a>).</p>

<p>Yesterday, a skier intentionally triggered a slide that broke 100 feet wide and ran a short distance down a wind-loaded slope adjacent to Beehive Basin in Big Sky (<a href="https://www.mtavalanche.com/node/31029"><strong><span>photo and details</span></strong></a>). Multiple avalanches in <a href="https://www.mtavalanche.com/node/31009"><strong><span>McAtee Basin</span></strong></a> near Big Sky, on <a href="https://www.mtavalanche.com/node/30935"><strong><span>Bridger Peak</span></strong></a><strong>, </strong><a href="https://www.mtavalanche.com/node/30937"><strong><span>south of Saddle Peak</span></strong></a> and in the <a href="https://www.mtavalanche.com/node/30949"><strong><span>Mount Bole Basin</span></strong></a> are recent evidence of instability that today’s new and wind-drifted snow will exacerbate.</p>

<p><span>The avalanche danger is CONSIDERABLE and may rise further if snow totals outpace forecasted amounts. Cautious route-finding and conservative terrain selection are essential to returning home safely. </span></p>