24-25

Wind slabs in hyalite

Date
Activity
Skiing

Toured into a north facing chute at around 9800 ft. Found a thick stubborn wind slab near the ridge that was difficult to trigger and did not really move a whole lot. In the middle of the chute I found a 6 in thick softer wind slab. There was a lot of variability in the snow throughout the upper elevations, and signs of active top and cross loading with gusty, swirling winds. 

Region
Northern Gallatin
Location (from list)
Hyalite - main fork
Observer Name
Jay Alford

A Mix of Dirt and Snow at History Rock

Date
Activity
Skiing

Ian and I drove up the Langhor Road in Hyalite Canyon in order to access the upper meadows of History Rock. We wrapped around and intersected with the trail in the mid-elevation meadows. Snow depths varied from 0" to 18." We toured into the middle of the three ski meadows before stopping to assess how the season's thin snowpack is evolving. The snowpack has a relatively simple, three layer structure. The lowest layer is beginning to show signs of weakening (faceting). However, the foundation of the snowpack was looking pretty good for now. ECTX. While we are optimistic for now, the snowpack is thin and can change quickly this time of year. There was evidence of wind in the History Rock area, this has likely built wind-slabs at higher elevations and more open terrain. 

The critical piece of information is that at mid to upper elevations the ground is mostly covered and we have a layered snowpack. We will stay tuned to how the snowpack evolves and how well subsequent storms bond to what we have on the ground. 

Region
Northern Gallatin
Location (from list)
History Rock
Observer Name
Dave Zinn

Flanders Snow

Date
Activity
Ice Climbing

From obs: "6-18" of coverage most areas in the Flanders drainage

Warming temperatures early in the afternoon were sending significant wet sloughs down Bobo and Big Sleep as witnessed from across the valley

Warming temperatures were creating perfect wet snow conditions for impressively large pinwheels on steeper solar aspects." 

 

Region
Northern Gallatin
Location (from list)
Flanders Creek

GNFAC Avalanche Forecast for Wed Nov 13, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Over the last month small storms have grown the snow depth to 10-18” at mountain weather stations (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span><span><span… log</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). After snowfall a week ago there were skier triggered and natural avalanches (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/avalanche-activity"><span><span><span><stro… activity</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Many of these avalanches were on wind-loaded slopes and broke at the base of the shallow snowpack (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/old-avalanche-crown"><span><span>… from northern Bridger crown</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Additionally, multiple skiers reported finding weak snow at the bottom of the snowpack in Hyalite, near Big Sky and the Bridger Range (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/snow-observations-list"><span><span><span><… page</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). The shallow snowpack changes a lot from day to day, but the avalanches and observations from last week are evidence that it is time to be prepared. Carefully assess the terrain and snowpack for avalanche potential, and carry the proper gear (beacon, shovel, probe).</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Avalanches are most likely where recent snow has drifted into thicker slabs. On steeper slopes this coincides with the best place to ski or ride because the deeper snowpack provides better coverage of rocks and hazards. Mark describes this early season dilemma in his recent video from </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=lA02PeWkO6g&amp;list=PLXu5151nmAvToI_ir… Lake</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, and advises to give the snow time after the snow falls and wind blows. If you see evidence of recent wind-loading, be patient and ride lower angle or non-wind loaded slopes.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The early season snowpack will be the foundation for future storms and is constantly changing. In Mark’s videos from the </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=W99OEptQWy8&amp;list=PLXu5151nmAvToI_ir… Range</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=RGXaUwH-XSA&amp;list=PLXu5151nmAvToI_ir… Park</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> last weekend, he shows that the snow has become weak from cold temperatures and clear nights. This could lead to fresh drifts being easier to trigger.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>If you intend to ride or cross steep slopes, watch for signs of instability such as recent avalanche activity, shooting cracks and collapsing. If obvious signs are absent, dig a quick snowpit to assess for instability.</span></span></span></span></span></span></p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar