17-18

<p>Today's avalanche concern is quite simple: it is windy with a lot of low density powder to blow around. Wind-loading is our #1 concern (and #2 and #3). Winds are blowing strong at ridgelines and also at lower elevations. The snow was measured at 4% density (96% air, aka cold smoke powder) and a mere puff of wind will blow this into thicker drifts (wind slabs). I expect slopes that are wind-loaded will easily avalanche with a human trigger and some will even break naturally. Look for wind slabs at ridgelines and gullies, on all aspects and elevations, and avoid them.</p>

<p>On slopes <u>without</u> a fresh wind-load, the snowpack is mostly strong and stable. On Sunday, Eric found stable conditions above Hebgen Lake (<a href="https://youtu.be/aqz9MPBYfyo"><strong>video</strong></a&gt;) and I found wind slabs on top of a stable snowpack (<a href="https://youtu.be/FqzP2G2hpcM"><strong>video</strong></a&gt;) at Lionhead. In the last few days, skiers and riders around Cooke City, Bacon Rind, Beehive, Hyalite and the Bridger Range have also found safe avalanche conditions.</p>

<p>I am lumping all the mountain ranges together even though snowfall amounts differ. In areas where SNOTEL only measured a couple inches, there may be much more at higher elevations based on what happened around Bridger Bowl and Big Sky.</p>

<p>Do not get on or underneath wind slabs. If you see shooting cracks in front of your skis or sled it might be too late. Just stick to the powder and you’ll have a good day. Additionally, wherever the new snow is deep, loose snow avalanches may unexpectedly knock you down and carry you into dangerous terrain. Throughout our advisory area the avalanche danger is rated <strong>CONSIDERABLE</strong> on all wind-loaded slopes and <strong>MODERATE</strong> on all others.</p>

<p>If you get out and have any avalanche or snowpack observations to share, drop a line via our <a href="https://www.mtavalanche.com/node/add/snow_observation">website</a&gt;, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a&gt;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>Near West Yellowstone and Cooke City, strong wind over the past 24 hours drifted 8-10” of new snow into unstable wind slabs. Wind slabs 1-3’ thick are likely near ridgelines, on steep rolling terrain, and along the edges and base of cliffs. Snowfall totals overnight are uncertain due to SNOTEL not telling data since 9 p.m. Since that time a few more inches are likely and more snow is expected today.</p>

<p>Doug went to Lionhead Ridge yesterday where he found Mark Staples from the Utah Avalanche Center had come back here to look at our 7-11 foot deep snowpack. They found fresh wind slabs on top of an otherwise stable snowpack (<strong><a href="https://youtu.be/FqzP2G2hpcM">video</a></strong&gt;). These wind slabs will grow and be easier to trigger with more snow and wind today. Avalanches breaking deeper than the new snow are not likely (<a href="https://youtu.be/aqz9MPBYfyo"><strong>video</strong></a&gt;). If snow today is deeper than expected, avalanches within the new snow and dry loose avalanches are possible on steep slopes.</p>

<p>Strong wind and continued snow make human triggered avalanches likely on wind-loaded slopes, which have a <strong>CONSIDERABLE</strong> avalanche danger today. Non-wind loaded slopes have a <strong>MODERATE</strong> avalanche danger.</p>

<p>The mountains near Bozeman and Big Sky got zero to 1” of snow overnight. Strong wind yesterday drifted snow from Saturday night into slabs that are possible to trigger. These slabs are found near ridgelines, along cliffs and steep rollovers. A few inches of snow and light wind today will not greatly decrease stability. However, note changing conditions and avoid steep slopes if you see cracking and collapsing, or if snowfall and wind loading are heavier than expected. The snowpack is generally stable aside from new snow, fresh wind slabs,&nbsp;and large cornices (<strong><a href="https://www.mtavalanche.com/images/18/big-cornices">photo</a></strong&gt;). Avalanche danger today is <strong>MODERATE</strong> on wind loaded slopes and <strong>LOW</strong> on non-wind loaded slopes.</p>

<p>If you get out and have any avalanche or snowpack observations to share, drop a line via our <a href="https://www.mtavalanche.com/node/add/snow_observation">website</a&gt;, email (<a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a&gt;), phone (406-587-6984), or Instagram (#gnfacobs).</p>