Looking up an avalanche in the Banana Couloir on Ross Peak that caught and carried two skiers on 12/5/22. Photo: Anonymous
Cut a wind slab from the top of the John around 2:30. 3-6” crown. 50-75’ wide. Ran down to the low grade below
<p><span><span><span><span><span><span>The southern mountains, including the area around Cooke City and West Yellowstone have gotten 2-3 feet of snow in the last week (</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>). This was followed by natural avalanche activity near Cooke City (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/22/large-natural-sheep"><span><span>… Mountain</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/images/22/large-natural-fox"><span><span><s… Mountain</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="http://www.mtavalanche.com/node/27060"><span><span><span><strong><span>…;) and Lionhead (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27046"><span><span><span><strong><span… Bowl</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/27021"><span><span><span><strong><span… Ridge</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Although snowfall has tapered off, wind has not. Wind redistributes snow and creates thick slabs. As far as the snowpack is concerned, it is still snowing out and the potential to trigger avalanches is likely. Weak layers of sugary or feathery snow are buried 2-4 feet deep, further compounding the instability.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Alex was in Cooke City last week and made </span></span></span></span></span></span><a href="https://youtu.be/_pW53Czv9vs"><span><span><span><strong><span><u><span>… video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> explaining his concerns with the new snow avalanching. Dave rode into Taylor Fork on Thursday and found similar conditions that he outlined in his </span></span></span></span></span></span><a href="https://youtu.be/aqqdf5N85DM"><span><span><span><strong><span><u><span>…;. The snowpack needs time to adjust to the last 7-days snowfall. It is not advisable to get into avalanche terrain as avalanches can break 2-4 feet deep; large and deadly. With wind and snow continuing, both natural and human triggered slides could occur and the avalanche danger is rated CONSIDERABLE on all slopes. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Yesterday, in the Bridger Range 2 skiers were caught in an avalanche. They were uninjured. We have no details on the 5 Ws (who, what, when, where, why), but the fact that skiers triggered and were caught in a slide is valuable bulls-eye data. Wind is blowing strong with gusts reaching 55 mph from the west at the ridgeline. Winds are also blowing and moving snow at mid-elevations. Yesterday’s 8” of new snow will be drifting in gullies and open slopes. Turn around at the first sign of cracking because that might be your only warning before triggering a slide. For today the avalanche danger remains CONSIDERABLE. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Yesterday, in Hyalite, a skier intentionally triggered a 12-18” deep wind-drifted slope in Lick Creek (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/22/skier-triggered-wind-load"><span>…;). Further in the range, Dave and his partner toured into Divide Peak and had concerns with new, wind-blown snow. In his </span></span></span></span></span></span><a href="https://youtu.be/u5SmVqnzMgg"><span><span><span><strong><span><u><span>…; he warns us about wind-loading. Gullies hold drifts and can be dangerous, especially for ice climbers. Further south around Big Sky the story is similar: without widespread weak layers we are worried about triggering thick drifts of wind-blown snow. Cracking in a drift is a clear sign they can avalanche and you should not go further. For today, it remains possible to trigger avalanches and the danger is rated MODERATE. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>If you get out, 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></p>
<p>The Island Park area has gotten 2 feet of snow in the last week. Although the snowfall has tapered off, the wind has not. Wind redistributes snow and creates new loading. As far as the snowpack is concerned, it is still snowing out. The snowpack needs time to adjust to this new load and it is not advisable to get into avalanche terrain. Avalanches can break 2-4 feet deep. They can be large and deadly.</p>
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Observed active windloading on the eastern side of Lick Creek today.
12-18 inch slab broke easily when ski cut and a small but very reactive cornice was rapidly building.
Photo: N. Roe
Two skiers triggered an avalanche while ascending the Banana Couloir on Ross Peak on the morning of 12/5/22. The skiers were approximately 150 ft from the top of the couloir when the avalanche broke 20 ft above the upper skier. The slide broke in wind drifted snow 6 inches deep and approximately 30 ft wide, across most of the couloir. The lower skier was waiting in a "safe spot on the side" but was also caught by the slide. The slide ran ~600 vertical feet, pulling out a deeper pocket of snow (1.5-2 ft deep) midway down the path. Both skiers were fully submerged as they were carried, but ended up partially buried near the toe of the debris. One skier had snow packed into his mouth and underneath his eyelids. They returned to the trailhead under their own power.
Two skiers triggered an avalanche while ascending the Banana Couloir on Ross Peak on the morning of 12/5/22. The skiers were approximately 150 ft from the top of the couloir. The avalanche broke 20 ft above the upper skier. The slide broke in wind drifted snow 6 inches deep and approximately 30 ft wide, across most of the couloir. The lower skier was waiting in a "safe spot on the side" but was also caught by the slide. The slide ran ~600 vertical feet, pulling out a deeper pocket of snow (1.5-2 ft deep) midway down the path. Both skiers were fully submerged as they were carried, but ended up partially buried near the toe of the debris. One skier had snow packed into his mouth and underneath his eyelids. They returned to the trailhead under their own power.
We skinned into the Divide Peak cirque to check out the conditions in Hyalite for the first time this season. On our tour we saw a couple of small R1-D1 slides that had broken within the new snow. At our first pit we saw HS at 124 cm with 10 cm of new snow. We had a ECTP 30 on facets 64 cm down from the surface. Next we dug on a SE aspect with a HS of 127 cm and 15 cm of new snow. We got an ECTN-3 within the new and old snow. More importantly, the wind was picking up throughout the day, and it was transporting snow. Our primary concern today was new snow, and in the next few days it will be wind drifted snow.
