This avalanche likely occurred on Tuesday, 21 Feb. Photo: N. Winning
Northerly aspect, around 9900' on this avalanche photo from Woody Ridge. Photo B. Fedlund
In Cooke City a large storm dropped 4.5" of snow water equivalent (4 feet of snow) and there were a few avalanches reported during and immediately after the storm. We saw one large avalanche on a south facing slope on Meridian, and a smaller wind-loaded slope that avalanched on Mt. Abundance (photo). We saw no other activity. Our concern is the interface between the old snow and new snow. The avalanche activity seemed to break here and on slopes with a wind-load it's worth being extra careful.
Meridian: R2, D2.5 (likely last night, 2/22)
Abundance: R3, D1.5 (maybe on 2/21)
In Cooke City a large storm dropped 4.5" of snow water equivalent (4 feet of snow) and there were a few avalanches reported during and immediately after the storm. We saw one large avalanche on a south facing slope on Meridian, and a smaller wind-loaded slope that avalanched on Mt. Abundance (photo). We saw no other activity. Our concern is the interface between the old snow and new snow. The avalanche activity seemed to break here and on slopes with a wind-load it's worth being extra careful.
Meridian: R2, D2.5
Abundance: R3, D1.5
In Cooke City a large storm dropped 4.5" of snow water equivalent (4 feet of snow) and there were a few avalanches reported during and immediately after the storm. We saw one large avalanche on a south facing slope on Meridian, and a smaller wind-loaded slope that avalanched on Mt. Abundance (photo). We saw no other activity. Our concern is the interface between the old snow and new snow. The avalanche activity seemed to break here and on slopes with a wind-load it's worth being extra careful.
Meridian: R2, D2.5 (likely last night, 2/22)
Abundance: R3, D1.5 (maybe on 2/21)
<p><span><span><span><span><span><span>The east wind in the Bridger Range is a frigid anomaly. It is blowing strong and yesterday it gusted to 70+ mph many times. In simple terms, east facing upper elevation slopes have been scoured while west facing slopes have been loaded. The reality of strong wind is that it does not always follow clean patterns and we expect a few pockets of dense, wind-drifted snow on all aspects. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Both Cooke City and the Bridger Range got hammered with snow and wind Saturday afternoon through Tuesday when 3-4 feet fell, reportedly more in Cooke City. The precise amount is not important. All slopes were loaded with heavy weight and many avalanches were seen in Cooke City while the Bridger Range only had a few. Skiers near Cooke City saw both large and small slab avalanches yesterday and sent in pictures and observations (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28255"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28252"><span><span><span><strong><span…;). In both the Bridger Range and Cooke City natural avalanches are not expected today, but triggering one is. Slopes need more time to adjust to the weight of the new snow (</span></span></span></span></span></span><a href="https://youtu.be/dBHp08f7F6g"><span><span><span><strong><span><u><span>…;). Stability is getting better, but we cannot rush the trend. Today is a day to avoid getting on steep slopes and enjoy the deep snow on low-angled terrain instead. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is rated CONSIDERABLE on all slopes. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The Gallatin Range, Madison Range and Lionhead area near West Yellowstone received 15-25” during the multi-day storm. Overall the snowpack held up well with only a few </span></span></span></span></span></span><a href="https://www.mtavalanche.com/weather/wx-avalanche-log"><span><span><span… reported</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>. Yesterday, Dave and his partner rode from Taylor Fork to Cabin Creek looking for avalanches and found none. Visibility was not perfect, but it was good enough to determine that natural slides were few and far between (</span></span></span></span></span></span><a href="https://youtu.be/QSMoCGCfUXA"><span><span><span><strong><span><u><span>…; and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28264"><span><span><span><strong><span…;). The concern throughout these ranges center around triggering avalanches on wind-loaded slopes and also on slopes that may harbor a lingering weakness three feet deep. With passing days the snowpack is getting more stable, but we know that some areas, like Lionhead, had weaker snow near the surface before this storm (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28195"><span><span><span><strong><span…;). Without obvious signs of instability the onus to find it lies with you. You can dig, test and decide, or you can just hope for the best.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is rated MODERATE on all slopes.</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><span><span><span><span><span><span> </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The mountains received 15” of snow with the recent, multi-day storm. The concern is triggering avalanches on wind-loaded slopes and also on slopes that may harbor a lingering weakness three feet deep. Without obvious signs of instability the onus to find it lies with you. You can dig, test and decide, or you can just hope for the best.</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.
Mountain temps at 4am are -28 to -10F.
We rode through Sunlight Basin, Sage Basin, and Cabin Creek today looking for avalanche activity from the most recent storm that dropped 15" of snow (1.5" of snow water equivalent) in the Taylor Fork area. We did not see any signs of recent avalanches. Today the wind blew from the NE, and it was drifting the new storm snow throughout Cabin Creek and Sage Basin. Since the wind is transporting the storm snow it is still possible to trigger an avalanche several days after the storm.
Photos of some recent natural avalanches near Cooke City today attached. All of the slides observed appeared to just involve new snow from the Feb. 20-21 storm. (occuring on all aspects, but primarily on NE aspects)
New snow: generally about 50-80cms of settled new snow from Feb. 20-21.
Quite a bit of collapsing experienced today while breaking trail, particularly in the lower elevations.
Snowpit attached from a SE aspect at 8500'. HS: 170.
ECTP15- 55cms down, at new/old interface.
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from 23 February email:
