On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was at the head of Sage Creek. Here, Alex is investigating the layering within the snowpack that lead to the avalanche. Photo: GNFAC
On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sage Basin. Photo: GNFAC
On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sunlight Basin. Photo: GNFAC
On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sunlight Basin. Photo: GNFAC
Myself and two partners were skiing in the crazies 3/17-3/18. Dug 2 pits and got similar results, ectn15 18cm down and n28 30cm down with depths of 300-400cm and no deeper pwls on N/NE aspects at 8300ft and 9600ft. No recent avalanche activity other than a few small 6in storm/wind slabs on southern aspects. Snowpack was very right side up everywhere we toured and had skied 3 different NW to E faces. On 3/18 we headed to ski a NE facing couloir at 10000ft, skinned/booted the first ~300ft and found similar snow to everywhere else. About halfway up hit a rocky section with some depth hoar, I noted plate crystals up to 1cm wide at ground. Should’ve turned around there but thought maybe it was just a short rocky section. I had also just measured the slope angle at 52 degrees which gave me false confidence there would be no developed slab. Wallowed through weaker snow for another ~50ft then finally decided to turn around due to the difficult boot packing, hitting our 3pm turn around time, and the weak snow pack. As I booted to the middle of the line to find better snow the slab broke off 10-20ft above me wall to wall. I was the only one caught and was carried 500ft of vertical. Didn’t get buried and no lost gear so extremely lucky all around. The avalanche was estimated D2/R4 with a 18-30in crown and 30ft wide.
Numerous slides observed on Saturday 3/18 on the flanks of Emigrant Peak during a tour up its east bowls. The largest ones seemed to be on SE aspects.
<p><span><span><span><span><span><span>Yesterday near Cooke City a snowmobiler triggered a huge deep slab avalanche, and the rider was luckily unharmed (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28695"><span><span><span><strong><span… and photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). The possibility for a person to trigger a similar avalanche on older, deep buried weak layers is the primary concern throughout our forecast area. Yesterday a skier reported a recent natural avalanche on Electric Peak which is another example of what someone could trigger today (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28706"><span><span><span><strong><span… and details</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). We have seen the majority of deep slab avalanche activity near Cooke City and West Yellowstone (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28673"><span><span><span><strong><span… observation</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=ncKRJpdC-iE"><span><span><span><strong>…;), where more snow fell over the last month, but the possibility to trigger a large, deep avalanche also exists near Bozeman and Big Sky (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28455"><span><span><span><strong><span… Peak slide</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28642"><span><span><span><strong><span… Bridgers slide</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The likelihood of avalanches has decreased since the most recent snow on Wednesday, but a person can still trigger an avalanche with large consequences. Before traveling on or underneath steep slopes, evaluate the snowpack for buried weak layers and previous wind-loading. Avoid heavily wind-loaded slopes and slopes where you suspect buried weak layers exist.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Additionally, a person can trigger avalanches of wind-drifted snow up to a couple feet deep that formed after the last snowstorm on Wednesday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/large-avalanche-mount-bole"><span… avalanche on Mt. Bole</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). These wind slabs can be harmful on their own, or trigger a larger avalanche deeper in the snowpack. Identify and avoid recently formed drifts of snow.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>On slopes that receive direct sunshine, the snow surface has turned to a melt-freeze crust during the last couple days. Small wet loose slides are possible where this crust melts. Although this type of hazard has been minimal, with another sunny day it is worth keeping wet loose avalanches in mind. Additional concerns include cornices that may become weak from the hot sun and break off, and roof avalanches around buildings that have a deep winter snowpack that could slide off metal roofs (</span></span></span></span></span></span><a href="https://www.newsbreak.com/island-park-id/2958869741874-9-year-old-survi… call earlier this week in Island Park, ID</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>).</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Today, heightened avalanche conditions exist and the 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></u></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></p>
<p><span><span><span><span><span><span>The possibility for a person to trigger an avalanche on older, deep buried weak layers is the primary concern. The likelihood of avalanches has decreased, but a person can trigger an avalanche with large consequences. Before traveling on or underneath steep slopes, evaluate the snowpack for buried weak layers and previous wind-loading and avoid heavily wind-loaded slopes, or slopes where you suspect buried weak layers exist.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>See </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=O-lUMunzE1k"><span><span><span><span><s…’s video</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> for a rundown on the aftermath of this week’s avalanche warning.</span></span></span></span></span></span></p>
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
D3 slab avalanche on SE corner of Giant Castle Mountain north of Pahaska, WY appears to have been triggered by a skier between 3/16/2023 and 3/18/2023. Outside Advisory Area. Photo: A. Billin
