From email 2/26/23: "I just talked with a fella that reported his buddy was buried up to his chest in an avalanche yesterday off of east abundance, near the cliffs. He reported a 4' crown and 200' wide. His buddy was snowmobiling."
Apologies for the day-late observations. We skied in the Maid of the Mist area. We saw signs of several cornice drops, some of which resulted in small or medium size slab avalanches on steep terrain (see photo), and others that resulted in minimal sluffing (no photo). None resulted in a widespread propagation like what happened on Blackmore a few days ago. This seemed encouraging. There were many parties skiing the bowl. We then tried to ski out on the south side of the Maid. We stopped to dig a pit at 8800 feet on a NE facing slope before entering the gully. We did a few CT tests and the results were not encouraging. We moved moved 100 yards to a more East facing aspect, and got similar results. I included an annotated photo of the first snowpit wall. Every layer sheared cleanly: CT6 @ 6" below the surface, CT2 @ 12" below the surface, CT3 @ 14" below the surface, CT15 @ 20" below the surface, CT21 @ 30" below the surface. It was like peeling an onion ;-) We skinned back up and over to ski out the more common exit in the trees.
This gully on the south side of Maid of the Mist is really nice but it feeds into a scary terrain trap. I don't see it skied very often and I feel like that's probably a good thing. That's part of my reason for asking to not share these obs publicly, or maybe I'm just being selfish...?
A rider observed recent avalanches on wind-loaded slopes near Lionhead on 2/25/23. Photo: K. Allred
<p><span><span><span><span><span><span>Yesterday near Cooke City, a large natural avalanche buried the Daisy Pass road (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28305"><span><span><span><strong><span… and details</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), a skier triggered and was caught in an avalanche near Round Lake (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/skier-triggered-slide-near-round-…;), and a large natural avalanche was seen on the east side of Henderson Mountain (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/natural-avalanche-e-henderson-ben…;). Recent strong winds drifted last week’s 4 feet of snow into thick slabs that are easy for a person to trigger, and could avalanche naturally if more weight is added from wind-drifted snow today. Avoid travel across steep wind-loaded slopes and minimize time spent below them. The avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on other slopes.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Early last week the mountains received 2-4 feet of snow (1.5-3.5” of snow water equivalent), and since Wednesday strong wind has drifted that snow into thicker slabs that are possible for a person to trigger. On Friday there were natural and human-triggered slides reported near Big Sky and Hyalite (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28293"><span><span><span><strong><span… triggered on Buck Ridge</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/23/large-natural-wind-slab-mt-blackm… on Mt. Blackmore</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/23/natural-cornice-collapse-beehive"… fall Beehive</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/28325"><span><span><span><strong><span… on Fan Mtn.</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Yesterday, in the southern Gallatin Range skiers intentionally triggered a small wind slab (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28319"><span><span><span><strong><span…;), and near Hebgen Lake skiers had small wind slabs collapse on low angle slopes (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28317"><span><span><span><strong><span…;). </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Overnight wind speeds increased everywhere, except the Bridger Range where speeds decreased slightly. Despite continued strong wind, most of last week’s snow has already been drifted into denser slabs, so slabs are not growing and slopes are getting relief from additional loading. With this break from loading, natural avalanches are unlikely, but recently formed wind slabs can be triggered by a person and still need a day or two to be fully trusted. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Assess the snowpack for signs of recently formed drifts which often appear as round, smooth pillows, and form below cornices, convex rolls and on the opposite side of scoured ridgelines. Travel on slopes that do not have recent drifts or are less than 30 degrees steep. Today the avalanche danger is MODERATE because human-triggered avalanches are possible.</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></p>
<p><span><span><span><span><span><span>Heavy snowfall is possible today along with strong winds which will create fresh, unstable slabs. These wind slabs will be easy to trigger and could break naturally. Recently formed wind slabs are also possible to trigger. Identify and avoid wind-loaded slopes.</span></span></span></span></span></span></p>
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Photo: taken from Cody Enterprise
From email 2/25/23: "... a good sized slab avalanche on Fan, NE Face. Crown height hard to estimate but looked like a 2’ or so. Maybe running on interface from when it got cold earlier in the week? Possibly deeper than that but sure could have loaded that much this week. Anyway- very white bed surface, good propagation, 200’ -300’ crown length, debris stopped on upper bench. D2.5. Likely triggered by cornice fall."
From email 2/25/23: "... a good sized slab avalanche on Fan, NE Face. Crown height hard to estimate but looked like a 2’ or so. Maybe running on interface from when it got cold earlier in the week? Possibly deeper than that but sure could have loaded that much this week. Anyway- very white bed surface, good propagation, 200’ -300’ crown length, debris stopped on upper bench. D2.5. Likely triggered by cornice fall."
