On Feb 6, 2022 we rode north of Cooke City and found 10-14" of new snow and a layer of buried weak facets that created unstable conditions. This setup makes avalanches possible to trigger on steep slopes. In this pit we had an ECTP13 break on weak facets a couple inches below the new snow. Photo: GNFAC
21-22
Small natural storm snow slides near Cooke
GNFAC Avalanche Forecast for Sun Feb 6, 2022
<p>Yesterday’s storm gifted Cooke City with 10” of low-density snow (0.6” of snow water equivalent), with possibly more in higher areas. This new snow adds weight above weak layers that are now buried 18-24” deep (<strong><a href="https://www.mtavalanche.com/images/22/buried-surface-hoar-layer-ynp-nea…;). Two days ago, these weak layers produced small skier triggered and natural avalanches (<strong><a href="https://www.mtavalanche.com/node/25722">photo and details</a></strong>, <strong><a href="https://www.mtavalanche.com/node/25725">details</a></strong>), and a skier triggered a large collapse of the snowpack on a low angle slope (<strong><a href="https://www.mtavalanche.com/node/25734">details</a></strong>). Today avalanches are easy to trigger and will be large enough to bury or injure a person. Be extra cautious of steep slopes, even if you don’t see obvious signs of instability. The snowpack needs time to be trusted with this new load of snow. Plan to avoid travel on and underneath slopes steeper than 30 degrees. Dangerous avalanche conditions exist and the avalanche danger is CONSIDERABLE.</p>
<p>Last night, 4” of snow fell in Hyalite (0.3” SWE) which is enough to keep avalanche danger heightened. Avalanches are possible to trigger, especially on wind-loaded slopes where 10” of low-density snow from earlier this week was drifted into thick slabs. Yesterday, climbers near Flanders witnessed a natural avalanche that was small, but would have knocked someone down and been deadly in that terrain (<strong><a href="https://www.mtavalanche.com/node/25744">details</a></strong>). Two days ago, skiers got unstable snowpack test results on weak layers 6-10” deep and triggered small avalanches in wind-drifted pockets (<a href="https://www.mtavalanche.com/images/22/very-small-wind-slab"><strong>pho…;). Last night’s snow adds weight to recent drifts and creates some smaller, unstable fresh slabs. Today, plan to avoid wind-loaded slopes, and watch for signs of instability like cracks shooting from your skis as a sign to avoid any steeper slopes. Avalanches are possible and danger is MODERATE.</p>
<p>Near West Yellowstone, Big Sky, and in the Bridger Range avalanches are unlikely or will be small. These areas got 5-10” of snow earlier this week which was drifted into slabs that might remain unstable in isolated areas. The last couple days wind was moderate to strong, but had minimal snow left to blow into drifts, and today wind has decreased to light with a few moderate gusts. Recently formed drifts have become generally stable. If you travel in steep terrain stay alert for areas of isolated instability, and carefully evaluate the snowpack for wind-loading and buried weak layers (<strong><a href="https://www.mtavalanche.com/images/22/northern-bridger-unstable-pit-res…;). Large avalanches are unlikely and the avalanche danger is LOW near West Yellowstone, Big Sky and the Bridger Range.</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>
King and Queen of the Ridge Results
Thank you and great work to everyone who participated in this year’s King and Queen of the Ridge event. This year you set a fund-raising record of $29,345! We are greatly appreciative of the support from everyone who hiked, donated, and raised money for The Friends of GNFAC. The King of the ridge this year is Casey Bloomer with 30 hikes, and Queen is Jennifer Allen with 22 hikes!
Weather and Avalanche Log for Sun Feb 6, 2022
AVALANCHE FATALITY - LIONHEAD
From obs 2/5/22: "We were planning on skiing ainger basin area. Snow seemed safe while we were skinning, but we dug 3 pits because the wind was so strong. got semi-unstable results each time, ect 12 to 18 with clean propagation around 4 to 9 inches down, depending on the slope."
Forecast link: GNFAC Avalanche Forecast for Sun Feb 6, 2022
Small Natural Avalanche, Flanders
Climbers on the big sleep on Saturday reported strong wind and blowing snow. They witnessed a wind slab that broke above the climb, and estimated that it was large enough to bury, injure, or kill a person.
From obs 2/5/22: "We hiked into Flanders to check out the Big Sleep ice climb. It was super windy with lots of blowing snow and the ice was thin so we decided not to climb it.
We witnessed a sizeable wind slab or sluff pour over the big sleep. It covered the whole climb for a second and probably would've slammed a climber off the route. Maybe 20 x 20 x 6 in slab but thats loose estimate."
From obs (2/5/22): "Attempted to ski the SE Couloir on Emigrant Peak today. As we approached, we noticed recent avalanche debris in the runout zone of the line. We approached carefully and it looked to be somewhat recent in the last few days. Not buried by much recent snow but also did not look fresh as of that day. I am guessing it was triggered by a collapsed cornice but with poor visibility it was challenging to see any sort of crown or broken cornice above us. We did not ski the couloir. I dug a pit in the open east facing bowl below at 9200 ft. The snowpack was between 55-75cm deep.
Forecast link: GNFAC Avalanche Forecast for Sun Feb 6, 2022
Large Natural Avalanche on Emigrant Peak
On Saturday, skiers on the SE couloir of Emigrant Peak found debris from a large natural avalanche. It appears to be more than 24 hours old.
From obs (2/5/22): "Attempted to ski the SE Couloir on Emigrant Peak today. As we approached, we noticed recent avalanche debris in the runout zone of the line. We approached carefully and it looked to be somewhat recent in the last few days. Not buried by much recent snow but also did not look fresh as of that day. I am guessing it was triggered by a collapsed cornice but with poor visibility it was challenging to see any sort of crown or broken cornice above us. We did not ski the couloir . I dug a pit in the open east facing bowl below at 9200 ft. The snowpack was between 55-75cm deep. In this location, the bottom 30cm of the snowpack were very large, well-developed facets with some depth hoar . I got ECTN 14 about 45cm up and ECTX on the facet/midpack interface (30cm up)."
Debris pile from a recent avalanche on the SE Couloir of Emigrant Peak. The avalanche appears to have occurred within the last few days and was likely triggered by a cornice fall. Photo: H. Darby