21-22

<p>A few inches of low density snow this morning will not increase the danger, but it will create some small hazards to watch out for. Strong westerly wind will drift any new snow into fresh slabs. These slabs will be shallow, maybe 4” deep, but could be easy for a person to trigger and propagate wide due to weak snow that recently formed near the top of the snowpack (<a href="https://www.mtavalanche.com/images/22/weak-layers-lionhead"><strong>pho…;, <strong><a href="https://www.youtube.com/watch?v=gR0EiO4JEeM&amp;list=PLXu5151nmAvT1nrM2… video</a></strong>, <a href="https://www.youtube.com/watch?v=7pv0tDJMuK4&amp;list=PLXu5151nmAvT1nrM2… video</strong></a>). Fresh drifts will unlikely be large enough to bury a person. If today’s strong wind doesn’t blow the low-density snow back to the sky, it could form thick dangerous slabs in favored, isolated areas. Before riding steep slopes watch for signs of instability like cracking of the snow surface or natural avalanches. Avoid fresh drifts in terrain where any size slide could be deadly due to pushing you into trees or over cliffs.</p>

<p>Avalanches deeper than today’s snow are unlikely, but shouldn’t be ruled out on slopes favored by recent wind-loading. Ian saw this yesterday near Cooke City where he found one slope with a weak layer buried deeper than anywhere else he had found it (<strong><a href="https://www.youtube.com/watch?v=nEC_zOu4JJg">video</a></strong&gt;), and a natural avalanche near Big Sky last Friday shows types of terrain where isolated instabilities might linger (<strong><a href="https://www.mtavalanche.com/node/25668">photo and details</a></strong>).</p>

<p>The forecast for snow has backed off for the mountains near West Yellowstone and the Bridger Range, and less than an inch is expected. It will take a couple inches of new snow for strong wind to form even small fresh drifts. If you choose to ski or ride in avalanche terrain it is always important to carefully assess the snowpack on each slope, only expose one person at a time, and carry proper avalanche rescue gear.</p>

<p>Today the snowpack is generally stable with small and isolated instabilities, and the avalanche danger is LOW. If more snow falls than is expected, danger will rise on wind-loaded slopes.</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>

<p>The snowpack is generally stable and avalanches are unlikely, but unlikely does not mean impossible. Small avalanches of wind-drifted snow or loose snow could be triggered and are most hazardous in high consequence terrain where they could push you over cliffs or into trees. There are isolated areas where a slab of wind-drifted snow could produce an avalanche large enough to bury or injure a person. Yesterday skiers near Big Sky saw a natural avalanche on Wilson Peak which involved recent, wind-drifted snow and appeared to be triggered by a cornice fall on Friday (<strong><a href="https://www.mtavalanche.com/node/25668">photo and details</a></strong>). If you choose to ski or ride in avalanche terrain it is always important to carefully assess the snowpack on each slope, only expose one person at a time, and carry proper avalanche rescue gear.</p>

<p>Yesterday Ian rode all over north of Cooke City, he did not see any avalanches and found stable snow. I saw similar stable conditions near Lionhead, but we both saw that the top of the snowpack has become a pile of weak layers (<strong><a href="https://www.mtavalanche.com/images/22/weak-layers-lionhead">photo</a></…;, <strong><a href="https://www.youtube.com/watch?v=gR0EiO4JEeM&amp;list=PLXu5151nmAvT1nrM2… video</a></strong>, <strong><a href="https://www.youtube.com/watch?v=7pv0tDJMuK4&amp;list=PLXu5151nmAvT1nrM2… video</a></strong>). We expect avalanches will break on these layers when we get enough snow. We have found similar weak layers on the surface of the snowpack throughout the advisory area over the last week (<a href="https://www.youtube.com/watch?v=VjIW7Pp-hz0"><strong>Mt. Ellis video</strong></a>, <a href="https://www.youtube.com/watch?v=SAKP0a0G9ks"><strong>Saddle Peak video</strong></a>, <a href="https://www.youtube.com/watch?v=6ax6l1PhUb0"><strong>Wheeler Mtn. video</strong></a>, <strong><a href="https://www.youtube.com/watch?v=I6AleixLxTI&amp;list=PLXu5151nmAvT1nrM2… Fork video</a></strong>). While these are not a problem right now, we want to have them in mind and be ready to ride in safer terrain if we get enough snow to create unstable conditions.</p>

<p>Today, the snowpack is generally stable with only small or isolated instabilities, and the avalanche danger is LOW.</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>