20-21

<p>Since Wednesday, nearly constant snowfall in the Bridger, Madison and Gallatin Ranges added up to 30” in the south and 54” in the north equal to 2.7-3.9”&nbsp; of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a>-SWE. New snow loaded a weak snowpack and resulted in avalanches. Yesterday, skiers reported seeing six avalanches in the Dudley Creek area, the Big Sky Ski Patrol used explosives to trigger slides that broke 3-5’ deep into old layers of weak snow, and Yellowstone Club ski patrollers remotely triggered an avalanche in the backcountry snowpack across their ropeline (<a href="https://mtavalanche.com/node/24145"><strong>Dudley Creek details</strong></a>, <a href="https://mtavalanche.com/images/21/remote-trigger-out-boundary-yc"><stro… photo</strong></a>). Yesterday at Mount Ellis, we saw widespread cracking on steeper slopes and stayed in lower angle terrain (<a href="https://mtavalanche.com/images/21/cracking-mount-ellis"><strong>photo</…;, <a href="https://www.youtube.com/watch?v=QOltFQqTy44&amp;list=PLXu5151nmAvQDzKmH…;). Look at our <a href="https://mtavalanche.com/weather/wx-avalanche-log"><strong>weather and avalanche log</strong></a> to track avalanche activity for each day during the storm cycle.</p>

<p>Winds are continuing to create drifts of snow sensitive to human triggers and Doug explains how the snowpack will remain dangerous for days from Bridger Bowl backcountry (<a href="https://www.youtube.com/watch?v=FeU_7Q_hhDI&amp;list=PLXu5151nmAvQDzKmH…;). Avoid steep wind-loaded slopes and use careful route-finding that minimizes exposure to steep terrain to travel safely in the backcountry today. Human-triggered avalanches are likely and the danger is rated CONSIDERABLE.</p>

<p>The mountains around Cooke City received 3-4’ of new snow equal to 3.1” of SWE since last Wednesday. Dangerous avalanche conditions exist on and under all steep slopes. Yesterday, skiers in the Sheep Creek drainage triggered an avalanche from a long distance away that broke 4’ deep and ran down into the gully below (<a href="https://mtavalanche.com/node/24155"><strong>photo and details</strong></a>), riders east of town spotted avalanches that failed naturally (<a href="https://mtavalanche.com/node/24160"><strong>photo and details</strong></a>), and skiers west of Cooke City in the thinner and weaker snowpack of the park triggered a collapse that rippled out&nbsp;from them (<a href="https://mtavalanche.com/images/21/cracking-east-cooke-city"><strong>det…;). On Friday, a skier triggered and was partially buried by a slide on Woody Ridge (<a href="https://www.mtavalanche.com/node/24075"><strong>photo and details</strong></a>). Fresh drifts of wind-loaded snow are adding weight to slopes and will be sensitive to triggers. Avoid steep wind-loaded slopes specifically and use careful route-finding that minimizes exposure to steep terrain in general. Human-triggered avalanches are likely and the danger is rated CONSIDERABLE.</p>

<p>Two feet of snow in the mountains around West Yellowstone since Wednesday loaded a weak snowpack. Over the weekend a rider triggered a large avalanche near Targhee Creek, luckily escaping without being caught (<a href="https://www.mtavalanche.com/node/24111"><strong>photo</strong></a&gt;). The snowpack in West Yellowstone has multiple persistent weak layers producing avalanches and will take time to stabilize after each storm (<a href="https://youtu.be/CI0HFvtLrf4"><strong>Lionhead video</strong></a>). Human-triggered avalanches are possible but with no new snow in the last two days the likelihood of triggering a large avalanche is going down. Evaluate the terrain and snowpack carefully to identify and avoid areas where you find signs of instability. The danger is rated MODERATE.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong>website<…;, email (<a href="mailto:mtavalanche@gmail.com"><strong>mtavalanche@gmail.com</strong></a…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>