21-22

<p>Monday and Tuesday’s 10” of new snow is getting blown into drifts which will be widespread. At ridgelines wind is strong and gusty from the W-SW and even at lower elevations the wind is strong enough to move snow. The drifts are piling onto a weak surface (sugary/faceted) and I expect them to easily crack and possibly avalanche, with the potential to propagate wider than we might think. Weak layers are found in the upper 12-18” of the snowpack. Ian rode into Buck Ridge yesterday and determined that wind-loading would create instability, and last night it blew at all elevations. Wind drifts will be found at ridgelines and in gullies. Unintentionally triggering a wind pillow, even a small one, could injure and/or bury you. Today, avalanches are possible on wind-loaded slopes and the danger is rated MODERATE. On slopes untouched by the wind, the danger is rated LOW.</p>

<p>The mountains south of Big Sky to West Yellowstone and Cooke City received 5-6” of snow on Monday and Tuesday. Winds have been mostly light and wind drifting could be found in a few isolated areas. Two skiers outside Cooke City found one of these slopes and triggered a slide in a steep, technical gulley near Goose Lake (<a href="https://www.mtavalanche.com/node/25697"><strong><u>details and photo</u></strong></a>). One person was carried 600’ and partially buried with his head under the snow. His partner rescued him within a couple minutes and was thankfully uninjured. In general, avalanches are unlikely today. Although there is weak snow in the upper 12-18” of the snowpack, a few inches of snow earlier in the week was not enough to tip the scales toward widespread instability. On Tuesday <a href="https://youtu.be/6aMGx0KCKFU"><strong><u>I was in Cooke City</u></strong></a> happily skiing in a snowstorm (yeah!), yet also concerned about loading which did not happen because the snow stopped (waah!). For today, the avalanche danger is rated LOW. As yesterday’s skier triggered avalanche illustrates, a low danger does not mean slides are impossible, just improbable.&nbsp;</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><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

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<p>In the last two days, 6-10” of low-density snow equal to 0.3-0.7” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314… water equivalent</a> (SWE) fell onto a variety of weak layers within the top 18” of the snowpack in the Bridger, Madison and Gallatin Ranges. The new snow will not be enough to tip the scales toward widespread instability. Consider recent avalanche activity to understand the concerns for the day. On the less likely end of this spectrum was a shallow but wide avalanche of hard windblown snow on Saddle Peak that occurred on January 25th (<a href="https://mtavalanche.com/node/25629"><strong>details, photos and video</strong></a>) and on the more likely end was a windslab triggered near Big Sky by a cornice collapse on Friday (<a href="https://mtavalanche.com/node/25668"><strong>details and photo</strong></a>) and small loose snow avalanches south of Bridger Bowl last Thursday (<a href="https://mtavalanche.com/node/25644"><strong>details and photo</strong></a>). Today, slab avalanches could be large enough to injure or bury a skier or rider and loose snow avalanches could result in an unpleasant tumble in technical terrain.</p>

<p>Dig down a couple of feet and perform a quick stability test to assess the upper levels of the snowpack before skiing and riding any steep slope (<a href="https://www.youtube.com/watch?v=sqn0KFZqXYs&amp;list=PLXu5151nmAvSpq8Ps… to test in less than 1-minute</strong></a>). If you don’t see signs of instability during your travel or in your stability test, stay warm and enjoy the new snow.</p>

<p>Today, human-triggered avalanches are possible and the danger is MODERATE.&nbsp;</p>

<p>The mountains around West Yellowstone and Cooke City picked up 4-5” of snow equal to 0.2-0.3” of SWE. This will soften the surface but will not significantly increase the avalanche danger. Yesterday in Cooke City, Doug noted that new snow was falling on weak facets at or near the surface and he would not be surprised if folks started triggering slides <em>if</em> the snow kept up (<a href="https://www.youtube.com/watch?v=6aMGx0KCKFU"><strong>video</strong></a&…;). Well, fortunately for stability and unfortunately for riding and skiing conditions, the snow did <em>not</em> keep up. Dig a snowpit to assess the top couple of feet of the snowpack and watch for signs of isolated instability as you travel. Pull back if you find localized areas with weaker snow. The fundamentals don’t change with the avalanche danger rating. Carry and be familiar with avalanche rescue gear and expose only one person at a time to avalanche terrain.</p>

<p>Human-triggered avalanches are unlikely and the danger&nbsp;is LOW.&nbsp;</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>