17-18

<p>Over the weekend, the mountains near Cooke City got 3 feet of snow equal to 3” of snow water equivalent (<a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2…;). Strong westerly wind on Saturday drifted this snow into slabs at all elevations. Moderate east wind last night formed slabs near ridgelines on aspects that don’t often have drifts. Today, wind slabs 1-4’ deep are easy to trigger near ridgelines, and on rollovers and cross-loaded gullies at all elevations. Avoid large cornices and slopes below, and avoid round pillows or whales of snow on steep slopes.</p>

<p>Cooke City has received steady snowfall this winter and is buried with over 12 feet of snow. On non-wind loaded slopes, large avalanches of recent snow are possible. Last weekend, a snowmobiler triggered a slide 2-4 feet deep. He was fully buried and recovered quickly by his partners (<strong><a href="https://www.mtavalanche.com/images/18/snowmobile-triggered-avalanche-ne…;). Similar slides are possible today. Careful snowpack and terrain evaluation are essential. Avalanche danger is <strong>CONSIDERABLE </strong>on wind loaded slopes and <strong>MODERATE</strong> on all other slopes.</p>

<p>Since Friday, the mountains near Bozeman and Big Sky got 1-2 feet of snow equal to 1.5-2” of snow water equivalent (<a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2…;), and near West Yellowstone got over 2 feet of snow equal to 2-2.5” of SWE. Strong west wind on Saturday drifted snow into slabs near ridgelines and at all elevations. I found these wind slabs in the northern Bridger Range on Saturday (<a href="https://youtu.be/0j-w-w85tDM"><strong>video</strong></a&gt;). Yesterday, a skier in Hyalite saw a small natural avalanche (<strong><a href="https://www.mtavalanche.com/images/18/small-wind-slab-near-mt-blackmore…;), and riders near Tepee Basin saw a natural avalanche on a heavily wind loaded slope (<strong><a href="https://www.mtavalanche.com/images/18/avalanche-wind-loaded-slope-tepee…;). Light to moderate east wind last night drifted snow into slabs near ridgelines and places not commonly loaded by wind.</p>

<p>Doug and I rode on Buck Ridge yesterday where we saw huge cornices (<strong><a href="https://www.mtavalanche.com/images/18/cornices-second-yellowmule">photo…;), zero avalanches or obvious sings of instability, and found a stable snowpack below 16” of fresh snow. Large cornices and fresh wind slabs are the main concern today. Avoid monstrous cornices, slopes below, and fresh drifts on steep slopes.</p>

<p>On non-wind loaded slopes, dry loose avalanches and slabs of recent snow are possible to trigger. These are more likely in areas that received more snow last night, like West Yellowstone. Avoid steep slopes if you see signs of instability like shooting cracks, collapsing, or fresh avalanches. Avalanche danger today is <strong>MODERATE</strong>.</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 Cooke City got 2-3 feet of snow equal to 2.5” of snow water equivalent (<strong><a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2…;) since Friday. Strong, gusty wind yesterday created consistent whiteout conditions and drifted snow into 1-4’ thick wind slabs at all elevations. This rapid, heavy loading event created dangerous avalanche conditions and large avalanches are likely today. Moderate wind and snowfall through today will continue to stress the snowpack and make large avalanches easy to trigger, especially on wind loaded slopes. Be cautious of smaller terrain, such as the steep edges of creek beds and gullies, where smaller slides are deadly because snow and debris will pile deep. <u>Avoid ALL steep slopes</u> and minimize time spent underneath them. Avalanche danger today is <strong>HIGH</strong> on wind loaded slopes and <strong>CONSIDERABLE</strong> on all other slopes.</p>

<p>The mountains south of Bozeman, near Big Sky, and near West Yellowstone got over a foot of snow equal to 1.5” of snow water equivalent (<strong><a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2…;) since Friday with 1” of that SWE since yesterday. Strong wind yesterday drifted snow into wind slabs 1-3’ thick that are easy to trigger today (<strong><a href="https://youtu.be/0j-w-w85tDM">video</a></strong&gt;). These slabs are found near ridgelines and at all elevations on steep, convex rollovers and cross-loaded gullies. On non-wind loaded slopes, dry loose avalanches and slabs of new snow are possible to trigger. Avoid wind loaded slopes, and avoid all steep slopes if you see signs of instability like shooting cracks, collapsing, or fresh avalanches. Avalanche danger today is <strong>CONSIDERABLE</strong> on wind loaded slopes and <strong>MODERATE </strong>on all other slopes.</p>

<p>The Bridger Range saw the least of the storm, and since yesterday received 4” of new snow equal to .4” of SWE in the northern part of the range and a trace to 1” of snow at Bridger Bowl. I went to Fairy Lake yesterday where strong winds were drifting recent snow and growing 1-2’ thick slabs that were easy to trigger (<strong><a href="https://youtu.be/qUooGmpF9Ss">video</a></strong&gt;). We found lower density snow underneath hard wind slabs, which made them more unstable and slower to gain strength. Moderate wind and snowfall today&nbsp;keeps wind slabs on edge and easy to trigger. These slabs will gain strength with time, but assessing their stability is tricky today. They may appear glued on with an initial ski cut, and then come loose on the second or third turn. Avoid wind loaded slopes today. Avalanche danger is <strong>CONSIDERABLE</strong> on wind loaded slopes and <strong>MODERATE</strong> on all other slopes.</p>