Advised a friend to stay off a slope, turned around and cut it trigger a slide. No burial no i injuries
<p>You are tired of hearing it and we are tired of it needing to be said, but that won't change the weak structure of the snowpack from West Yellowstone through the Bridger Range. On Trapper Ridge yesterday, I found a shallow, very weak snowpack where avalanches are less likely because it lacked the critical ingredient of a slab of more cohesive snow above the sugar (<a href="https://www.youtube.com/watch?v=nJ3VufFgj1E"><strong>video</strong></a&…;). This is the exception. Nearby in Lionhead the day before, Alex saw recent avalanches, heard "whumphs" and had unstable snowpit results (<a href="https://www.youtube.com/watch?v=HtHMcXwo3mw&list=PLXu5151nmAvQDzKmH…;, <a href="https://www.mtavalanche.com/images/21/lionshead-ridge-profile-jan-23"><… profile</strong></a>, <a href="https://www.mtavalanche.com/images/21/natural-avalanche-near-lionhead">…;). This corresponds with what he and Doug found at Buck Ridge last week (<a href="https://youtu.be/fUK0nUTBSvU"><strong>video</strong></a>,<strong> </strong><a href="https://www.mtavalanche.com/images/21/muddy-crk-profile-jan-21"><strong… profile</strong></a>). This week skiers and riders reported avalanches breaking naturally deep in the snowpack and continue to hear "whumphing" and get unstable test results (<a href="https://mtavalanche.com/avalanche-activity"><strong>avalanche activity list</strong></a>). In addition to weak snow near the ground, a layer of surface hoar is now buried 8-10" deep. Avalanches will occur on this layer when it gets loaded by more snow. </p>
<p>Three days have passed since the last new snow and weak layers are adjusting. Avalanches are less likely but don't be fooled into thinking that weak snow is getting stronger or that riding and skiing steep terrain is a sustainable practice right now. Manage terrain carefully because large, destructive avalanches remain possible. The danger is rated MODERATE.</p>
<p>Avalanches in Cooke City are breaking 12-18" deep on a layer of feathery snow crystals buried by the last storm. Two days ago, a rider was buried to his waist north of Sheep Mountain, he was okay but the sled was trashed (<a href="https://www.mtavalanche.com/node/23885"><strong>limited details</strong></a>). Three days ago, snow bikers triggered a pair of avalanches on the other end of Sheep Mountain, both escaped, but the slides were large enough to send a skier or rider on an unpleasant trip down the mountain (<a href="https://mtavalanche.com/node/23899"><strong>photos and details</strong></a>). Skiers close to Cooke City in Yellowstone National Park reported widespread collapsing and we are still receiving new photos of natural avalanches that broke within the last week (<a href="https://mtavalanche.com/images/21/republic-mountain-avalanche"><strong>…;). Look at the <a href="https://mtavalanche.com/photos"><strong>photos page</strong></a> and follow the <a href="https://mtavalanche.com/weather/wx-avalanche-log"><strong>weather and avalanche log</strong></a> to stay up to date. The layer of buried surface hoar is not universal in its distribution but it is best to assume that it is as I explained in my Cooke City videos last week (<a href="https://youtu.be/J9oQHYge_gM"><strong>video1</strong></a>, <a href="https://youtu.be/J9oQHYge_gM"><strong>video2</strong></a>). In addition to this reactive layer, some slopes harbor a weak layer of sugary snow 2-3' deep.</p>
<p>Navigation in avalanche terrain requires careful planning and assessment. Human triggered avalanches are possible and the danger is rated MODERATE.</p>
<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong>website<…;, email (<a href="mailto:mtavalanche@gmail.com"><strong>mtavalanche@gmail.com</strong></a…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>
See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:
From Obs: "I skied into Maid of the Mist today, it looks like part of a cornice fell and it failed on a wind slab from last weekend’s snow. It did not step down to the depth hoar. Photo: S Reinsel
Skiers reported a natural avalanche on Ernie Miller Ridge. Occurred with minimal new snow on a layer of weak depth hoar.
A natural avalanche on Ernie Miller Ridge failed on deeply buried facets earlier in the week on an east aspect. Skiers continue to report loud whumphs in the area. Photo: R. Wofford
From email, "A slab avalanche observed on Mt. Republic, northerly aspect, 8,600'." Photo: B Fredlund
Hey GNAFC,
Enjoyed a sunny tour today to Middle Peak and dug a pit below the ridge at approx 9980 ft, S facing. Attached is our pit data showing a depth of 110 cm with several slab layers (please don’t post this photo). We did not find a stout Nov or Dec crust near the ground nor buried surface hoar from before 01/20 wind. Of concern, ECTP20 at 90 cm on the hard slab from last Wednesday’s wind event. Also ECTP22 and PST35/100 END at the basal facets.
Noted a few deep slab avalanches mainly on east facing aspects that appeared 1-2 weeks old. See additional photo by Shane K from Middle Peak looking into Beehive Basin. These seemed the break a few hundred feet off of ridge, mid-path. Otherwise, found some new snow dry loose around buttresses and rocks on most other aspects. No cracking/collapsing.
Stay safe and thanks for all you do!
Sledded over Lulu to wilderness boundary today, then toured up around Goose Lake. Observed numerous human and sled triggered avalanches. All on S aspects in the 9 to 10k range, depths around 30 cm, D1R2. Dug at Goose Lake, found surface hoar buried 35cm down, ECTN. I suspect the surface hoar was involved in the avalanche events we observed based on crown depths. Seems to only be reactive on S aspects? Sled tracks everywhere. Also may have seen the avalanche mentioned in the advisory... it’s E of Huckleberry not N but close enough! Looks like it could have jacked up a sled but still only D1.
Hello,
We toured in Bacon Rind today and observed a natural avalanche on Ernie Miller Ridge. It was on an east-facing aspect on the north end of the ridge and after looking at Cal Topo maps somewhere in the 30-34 degree range. I believe it broke on the facets/depth hoar at the bottom of the snowpack as that is where we had failure in our pits but I do not have actual evidence of that. For reference, we had an ECTP 14 and an ECTP 21 on the west and east faces of Bacon Rind respectively. We also observed numerous whumpf's in flat meadows. I'm sure you have already heard reports of this avalanche but I thought I'd let you know anyway.
Thank you for all that you do,
Brisman
