17-18

<p>Over the last three days the mountains near West Yellowstone and Cooke City got 1-2 feet of new snow equal to 1-1.5” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a> (SWE). This new snow is a small amount of stress on top of a generally strong, 7-12 foot deep snowpack. Wind loaded slopes and large cornices are the main avalanche concerns today.</p>

<p>On Friday, Eric and I saw huge cornices and avoided wind loaded slopes in Tepee Basin (<a href="https://www.youtube.com/watch?v=36zb5uaURaQ"><strong>video</strong></a&…;), and skiers near Bacon Rind found easy to trigger wind slabs (<a href="https://www.mtavalanche.com/photos"><strong>photo</strong></a&gt;). Moderate south to east wind over the last 24 hours drifted snow into slabs 1-2’ deep. Due to the less common wind direction these slabs may be found in unusual locations like mid-slope and the west side of ridgelines. Stronger northwest wind this afternoon will drift new snow into fresh, easy to trigger slabs. Avoid wind loaded slopes near ridgelines and pillows of snow below cliffs and on convex rolls.</p>

<p>On non-winded loaded slopes avalanches breaking in the new snow are possible, especially as more snow falls today. Avoid steep slopes if you see shooting cracks or collapsing in the new snow and be cautious of dry loose avalanches in consequential terrain.</p>

<p>Today, avalanche danger is <strong>CONSIDERABLE</strong> on wind loaded slopes. Non-wind loaded slopes have a <strong>MODERATE</strong> avalanche danger.</p>

<p>The mountains near Bozeman and Big Sky got only 1-2” of new snow the last three days. Strong wind Friday formed drifts near ridgelines, below cliffs and in steep gullies. A skier triggered a small slab yesterday in Hyalite (<strong><a href="https://www.mtavalanche.com/images/18/skier-triggered-avalanche-hyalite…;), and on Friday Doug found fresh drifts in gullies. These wind slabs are harder to trigger today, but possible, and especially harmful if caught over cliffs or tight trees.</p>

<p>Large cornices continue to grow and can collapse naturally with new snow and wind or under the weight of a person. Cornices often break farther back than expected (<a href="https://www.mtavalanche.com/images/18/cornice-failure-hyalite"><strong>…;). Stay a far distance back from these monsters along ridgelines and avoid slopes directly below.</p>

<p>Stronger wind this afternoon will drift new snow into fresh slabs that are possible to trigger. On non-wind loaded slopes, avalanches breaking in the new snow and dry loose avalanches are possible with greater amounts of snow today. More snow today and stronger wind make avalanches possible and danger is rated <strong>MODERATE</strong> on all 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>

<p>The mountains near West Yellowstone picked up roughly a foot of new snow out of the latest storm system. Yesterday, Alex and I rode in Tepee Basin in the southern Madison Range and found wind loading to be the primary concern (<a href="https://www.youtube.com/watch?v=36zb5uaURaQ"><strong>video</strong></a&…;). Skiers on Ernie Miller Ridge near Bacon Rind found similar conditions (<a href="https://www.mtavalanche.com/photos"><strong>photo</strong></a&gt;).</p>

<p>Today, wind slabs 1-3’ deep will easily fail under the weight of a skier or rider. Watch for and avoid wind loaded slopes, specifically near ridgelines and steep convex rolls. Storm slabs and dry loose slides are less of a concern, but could still be triggered on steep sheltered slopes.</p>

<p>In addition to new snow instabilities, cornices continue to grow by the day. These overhanging monsters will be under a lot of stress from the latest storm. Give them a wide distance along the ridgelines and avoid spending time on slopes beneath them.</p>

<p>Today, human triggered slides are likely on wind loaded slopes which have a <strong>CONSIDERABLE</strong> avalanche danger. Non-wind loaded slopes have a <strong>MODERATE</strong>&nbsp;avalanche danger.</p>

<p>The mountains around Bozeman, Big Sky and Cooke City did not get hit nearly as hard with new snow, however, these areas did receive a heavy amount of wind. Yesterday, most areas saw wind gusts between 40-50 mph, which moved snow around in higher elevations. Doug was in Hyalite yesterday and found gullies to be packed with fresh wind drifts. These drifts were mostly glued on, but he still avoided them and mentioned the situation could be different in the alpine.</p>

<p>Fresh wind drifts will be stubborn today, but still hold the potential to fail with the proper trigger (<a href="https://www.youtube.com/watch?v=pL3sFBfPucM&amp;t=0s&amp;list=PLXu5151n…;). Be cautious when traveling around wind loaded slopes, specifically in steep high consequence terrain. The gullies in Hyalite are a perfect example of terrain where even a small wind slab can have severe consequences.</p>

<p>Cornices are an additional problem. They can break farther back than expected and can trigger slides on the slopes below (<a href="https://www.mtavalanche.com/images/18/large-natural-slide-northern-brid…;).</p>

<p>Today, natural avalanches are unlikely, but human triggered avalanches remain possible on wind loaded slopes which have a <strong>MODERATE</strong> avalanche danger. Non-wind loaded slopes have a <strong>LOW </strong>avalanche danger.</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>