21-22

<p>A foot of fresh snow (1.3” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314… Water Equivalent</u></a>) and moderate to strong west winds have built 2-3 ft deep wind drifts that will be easily triggered today across much of the Bridger Range. The area around Bridger Bowl got half as much new snow and will have thinner drifts. Look out for and avoid steep wind-loaded slopes. Don’t let powder fever take over. Stick to lower angled slopes and give the new snow time to settle and bond. An additional concern is the weak snow at the ground which just got stressed by a big load of new snow. If a slide broke on these lower layers it would be much larger and even more dangerous. Triggering avalanches is likely on windloaded slopes, where the avalanche danger is CONSIDERABLE. On non-windloaded slopes the avalanche danger is MODERATE.</p>

<p>Five to 8” of new snow drifting into cohesive slabs means it is possible to trigger 1-2 ft deep avalanches today. In the southern ranges this new snow fell onto a freshly buried surface hoar layer (<a href="https://www.youtube.com/watch?v=zlREIgIkphs"><strong><u>Taylor Fork video</u></strong></a>), which will make avalanches break more easily. Non-windloaded slopes don’t have a thick or cohesive enough slab of new snow for it to be problematic. Cracks shooting out in front of your skis or sled indicate you’ve found a slope with a reactive wind slab. The avalanche danger is MODERATE on windloaded slopes and LOW elsewhere.</p>

<p>Only 2-3” of snow fell in the Lionhead area and near Cooke City. This is not enough new snow to increase the avalanche hazard. Watch out in very steep terrain where getting knocked off your feet by a small avalanche would be problematic and also be on alert if you find an isolated area with deeper drifts where you could trigger a larger slide. Overall, large avalanches are unlikely 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><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

<p>The snowpack is generally stable other than small, surface-level instabilities created by yesterday’s 1-3” of new snow. Yesterday, skiers noted relatively small and harmless slabs up to 5” deep predictably breaking near ridgelines where winds formed small drifts. Today, these could be a problem in steep or technical terrain where they could knock you off your feet or sled but would be unlikely to bury a skier or rider. The danger associated with these small avalanches will increase if snowfall intensifies this afternoon.</p>

<p>Beyond these superficial instabilities, keep the fundamentals in mind. We have a layered snowpack and as Ian found in the Flanders drainage on Tuesday, there are isolated areas of instability in a sea of overall stability (<a href="https://youtu.be/-ha6ugs0Wgs"><strong>video</strong></a&gt;). Assess the snowpack with a pit and a quick stability test to make a <em>slope-scale </em>forecast before entering avalanche terrain. If you are surprised by less stable results, dial your objectives back as Ian did in Hyalite.</p>

<p>Finally, we have a new weak layer buried under a few inches of snow in the Southern Madison and Southern Gallatin Ranges and the Lionhead and Cooke City areas that will likely become a problem as it gets buried deeper. Ian found this stripe of feathery surface hoar buried in the Taylor Fork yesterday, Alex and Doug saw it in Cooke City and at Lionhead earlier in the week and skiers and riders have sent in observations confirming that this layer is widespread (<a href="https://www.youtube.com/watch?v=zlREIgIkphs"><strong>Taylor Fork video</strong></a>, <a href="http://www.mtavalanche.com/images/22/buried-surface-hoar-near-cooke-cit… City photo</strong></a>/ <a href="https://youtu.be/FOJv3cTQ8rs"><strong>video</strong></a&gt;, <a href="https://youtu.be/g7Pl9-raU7g"><strong>Lionhead video</strong></a>). Follow along for more information as conditions evolve.</p>

<p>Today, human-triggered avalanches breaking deeper than the thin layer of new snow are unlikely and the danger is rated 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>