19-20

<p>Over the last 24 hours the mountains near West Yellowstone and the southern Madison Range got 7-12” of snow equal to 0.7-1.2” of <u><a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a></u> (SWE). Snowfall was heaviest overnight and light snow will continue today. Moderate to strong southwest wind formed thick drifts that will grow larger today and overload buried weak layers (<strong><a href="https://www.youtube.com/watch?v=QoHpKz6J52s&amp;feature=youtu.be">video…;). These drifts can easily be triggered and can break deeper and wider on sugary snow near the ground (<strong><a href="https://www.mtavalanche.com/images/19/shallow-and-unstable-lionhead">ph…;, <strong><a href="https://www.mtavalanche.com/sites/default/files/styles/very_large_1200w…;). Even without wind-loading the new snow is enough to create slabs that can avalanche and be large enough to bury or injure a person. Today all steep slopes and runout zones should be avoided. Dangerous avalanche conditions exist and avalanche danger is CONSIDERABLE.</p>

<p>Near Cooke City, Big Sky and the Bridger Range strong southwest wind last night created fresh drifts that are easy to trigger. These mountains received 3-7” of snow yesterday, and over 20” in the last week. Today moderate westerly wind will continue to grow drifts. Steep wind-loaded slopes should be avoided. Watch out for round pillows of snow and slopes below large cornices.</p>

<p>A less likely, but certainly deadly avalanche can be triggered on weak layers buried near the bottom of the snowpack. Yesterday Doug went to Buck Ridge and saw three avalanches that broke on weak layers near the ground (<strong><a href="https://youtu.be/hVWTWK_GaBs">video</a></strong&gt;). Dave was in Cooke City where the 40”+ of snow that fell since the beginning of 2020 was the main avalanche concern, and he emphasized the possibility of larger avalanches breaking deep in the snowpack (<strong><a href="https://www.youtube.com/watch?v=_VHfcZztwYQ">video</a></strong&gt;). Wind loaded or not, avoid any steep slope with&nbsp;suspected buried weak layers. See our <strong><a href="https://www.youtube.com/playlist?list=PLXu5151nmAvSbcbVfoR785MxkqkNVy8P…; and <strong><a href="https://www.mtavalanche.com/photos">photos</a></strong&gt; to get a better idea of where these weak layers exist in the snowpack. Avalanche danger is CONSIDERABLE on wind loaded slopes and MODERATE on non-wind loaded slopes.</p>

<p>The northern Gallatin Range did not get any snow over the last 24 hours and has a generally stable snowpack. On Saturday I toured to Mt. Blackmore and the main avalanche concern was fresh drifts of snow (<u><strong><a href="https://www.youtube.com/watch?v=Fdgt5Mp8E6s&amp;list=PLXu5151nmAvSbcbVf…;). These mountains received 10-15” of snow last week. Strong wind last night drifted this snow into fresh slabs that are possible to trigger. Watch for cracking of the snow surface as a sign fresh drifts are unstable, and carefully assess consequences of an avalanche before riding steep slopes. Avalanche&nbsp;danger is MODERATE on wind loaded slopes and LOW on non-wind loaded slopes.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an&nbsp;<u><strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong></u>, email us (<u><strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong></u&gt;), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>