22-23
Investigation of avalanche fatality on Crown Butte
We looked at the avalanche that killed a snowmobiler yesterday (12/31/22) on Crown Butte near Cooke City. It occurred on a southeast facing slope at 9,800 feet elevation. At the crown the avalanche was 1.5-2 feet deep on average, and up to 4 feet at the deepest. It broke 500 feet wide and ran 600 vertical feet. It was a hard slab avalanche that broke on weak, sugary snow, and was large enough to break trees or destroy a car. Our deepest condolences go out to the family and friends of the victim, and those involved with the rescue and recovery.
Surface hoar south to south east aspects, potentially more aspects, will confirm later this afternoon.
Warm creek
Today my partner Henry and I toured around the fields between Barronette and Warm Creek pass. Overnight snow was approximately 2” with storm total about 12”. We dug a pit on an E aspect at 8,200’, HS 152cm, ECTX, CT23 (RP) 50cm down on a density change. Aside from the density change that produces CT result, and 15cm of basal facets, the snow pack was right side up with no signs of instability or natural avalanche activity throughout the day. Ski quality was excellent.
Slide in Sheep
Snowmobile triggered avalanche west face of Sheep
Surface hoar at buck ridge
Surface hoar south to south east aspects, potentially more aspects, will confirm later this afternoon.
Snow pit in wheeler gulch, small slide at Bridger bowl
GNFAC Avalanche Forecast for Sun Jan 1, 2023
<p><span><span><span><span><span><span>Yesterday’s fatality is the clearest possible indicator that the snowpack remains capable of producing large and dangerous avalanches (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/crown-butte-avalanche-fatality-bu…; </span></span></strong></span></span></span><a href="https://www.mtavalanche.com/images/23/crown-butte-avalanche-fatality-fu…;). In addition, there were snowmobile triggered slides on Sheep Mountain near Cooke City (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=Tsr8x3PCG3s"><span><span><span><strong>…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27426"><span><span><span><strong><span…;) and another along Lionhead ridge (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27430"><span><span><span><strong><span…;). These slides all broke on weak layers in the lower snowpack (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=AzCUIW7Fr_0"><span><span><span><strong>… Fork video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). You could also trigger dangerous slides within the snow that’s fallen over the last week (particularly where it has been wind drifted) or on a weak layer buried just beneath it. Although the snowpack is somewhat shallower in northern areas than further south, the list of concerns is the same. With no new snow or wind drifting, avalanches are a hair less likely today than yesterday, but still very much possible and they will be large. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Once they get a substantial break from the stress of new snowfall these layers will eventually stop producing avalanches, however, we are clearly not there yet. In the meantime, don’t try to outsmart the persistent weak layers. These layers are not producing consistently unstable snowpack test results, but they are producing avalanches. Continued patience (avoiding avalanche terrain) and adherence to safe travel protocols (riding one at a time, carrying rescue gear, and watching your partners for a safe spot) are the best ways to manage this concern. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Human triggered avalanches are possible and the avalanche danger is MODERATE.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Please share avalanche, snowpack or weather observations via our</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>…; </span></span></span></span></span></span><span><span><span><strong><span><u><span><span>website</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, email (</span></span></span></span></span></span><span><span><span><strong><span><span>mtavalanche@gmail.com</span></span></strong></span></span></span><span><span><span><span><span><span>), phone (406-587-6984), or Instagram (#gnfacobs). </span></span></span></span></span></span><span><span><span><span><span><span> </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>In Island Park, slides can break on weak layers in the lower snowpack, within the snow that’s fallen over the last week (particularly where it has been wind drifted) or on a weak layer buried just beneath it. There was an avalanche fatality yesterday near Cooke City and a deep slide triggered along Lionhead ridge. Continued patience (avoiding avalanche terrain) and adherence to safe travel protocols (riding one at a time, carrying rescue gear, and watching your partners for a safe spot) are the best ways to manage these concerns. </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.