GNFAC Avalanche Forecast for Wed Feb 8, 2023
<p><span><span><span><span><span><span>The Bridger, Gallatin and Madison Ranges and Lionhead area, have another day of strong wind with a few inches of new snow falling. West to southwest wind is averaging 15-30 mph and gusting to 50 mph. Yesterday, as the snow was actively loading, I was able to intentionally trigger a slide in Island Park near West Yellowstone (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28026"><span><span><span><strong><span… and video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), sledders triggered a slide on Two Top (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28041"><span><span><span><strong><span…;), and drivers saw road cuts avalanching in Bridger Canyon (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28024"><span><span><span><strong><span…;). If it is snowing and blowing, triggering avalanches gets easier. Recent avalanche activity and shooting cracks, like I got yesterday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/23/cracks-shot-out-my-feet-and-trigg…;), are a clear sign that slopes are unstable and should be avoided. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The mountains have weak layers of sugary snow in the top 2-3 feet of the snowpack that are reactive in stability tests. We have seen these layers in the</span></span></span></span></span></span><span><span><span><strong><span><span> </span></span></strong></span></span></span><a href="https://www.youtube.com/watch?v=ITX7Ic3eFYM&list=PLXu5151nmAvTi1DBS…; </span></span></strong></span></span></span><span><span><span><span><span><span>of the Bridger Range</span></span></span></span></span></span><span><span><span><strong><span><span>,</span></span></strong></span></span></span><span><span><span><span><span><span> in </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27919"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=LZ9aWLM7J2A&list=PLXu5151nmAvTi1DBS…. Wheeler</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.youtube.com/watch?v=6zNtBZuvEWw&list=PLXu5151nmAvTi1DBS… Basin</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, and near </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=1izHP8-z8gY&lc=UgwTk8WVKJoymJc7HyN4… Yellowstone</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>. A skier triggered a large slide on a north facing slope on Hyalite Peak on Saturday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28036"><span><span><span><strong><span… and pics</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), a sledder noted a slide on Sage Peak that slid on Monday. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Stay off of wind-loaded terrain and be wary of buried weak layers since they can still avalanche on a few slopes. Triggering avalanches on wind-loaded terrain is likely and the danger is rated CONSIDERABLE on these slopes. On slopes without a wind-load, the danger is rated MODERATE. </span></span></span></span></span></span></p>
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<p><span><span><span><span><span><span>The mountains around Cooke City received 9” of snow Monday and Tuesday with very little wind, but that has changed. Wind gusts are in the mid 30’s and recent snow is getting blown into drifts. Wind is not confined to the ridgetops (it rarely is around Cooke City) and fresh wind-drifts will easily be triggered. These mountains also have a </span></span></span></span></span></span><span><span><span><span><em><span>new</span></em></span></span></span></span><span><span><span><span><span><span> weak layer of sugary facets about 1-2 feet under the surface which Alex forewarns us about (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=XhCVFXtNsKg"><span><span><span><strong>…;). In general, today is a day to avoid slopes that have been wind-loaded. Near Sheep Mountain on Monday, riders triggered a small slide on one of these weak layers (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28021"><span><span><span><strong><span… and details</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). There is no free lunch: you have to dig, look for weak layers and avoid steep slopes as soon as you find instability. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>For today, the avalanche danger is rated CONSIDERABLE on all wind-loaded slopes and MODERATE on all others.</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></p>
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<p><span><span><span><span><span><span>The mountains have another day of strong wind with a few inches of new snow falling today. If it is snowing and blowing, triggering avalanches gets easier. Yesterday, as the snow was actively loading, I was able to intentionally trigger a slide in Island Park near West Yellowstone (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28026"><span><span><span><strong><span… and video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>) and sledders triggered a slide on Two Top (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/28041"><span><span><span><strong><span…;). Stay off of wind-loaded terrain and be wary of buried weak layers since they can still avalanche on a few slopes. Triggering avalanches on wind-loaded terrain is likely today.</span></span></span></span></span></span></p>
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Sledder triggered slide, Two Top
From FB: Had some tourists in the shop trigger an avalanche on two top yesterday. Didn't get exactly where or much details. Steep tracked up slope they set off. Just a partial sled burial.
Sledder triggered slide, Two Top
From FB: Had some tourists in the shop trigger an avalanche on two top yesterday. Didn't get exactly where or much details. Steep tracked up slope they set off. Just a partial sled burial.
Wind slab over facets
We toured up to the bacon rind ridge, descended a southwest aspect, and then headed over and up to the Ernie Miller Ridge.
In sheltered locations, there was approximately 15 cm of storm snow from Sunday into Monday.
On an east-southeast aspect off of Ernie Miller between approximately 9000-9700', we found widespread 20-25 cm thick 1F wind slab sitting on 1 mm facets. The slab was moderately resistant in hand shears and remained intact once isolated. It was not reactive to our jumping on small test slopes. We observed no cracking during our ascent and saw no signs of reactivity during our descent.
Above approximately 9700', the surface was largely scoured and there was a thin wind skin.
We observed similar facets below the storm snow on our ascent of a southwest aspect between 8000-8700' on the way back up to the bacon rind ridge.
Natural Avalanche on Sage Peak
From FB: We saw a fresh break on the west face of sage peak last night, I would guess around 9500’.
Natural Avalanche on Sage Peak
From FB: We saw a fresh break on the west face of sage peak last night, I would guess around 9500’.
Avalanche on Hyalite Peak
Me and a buddy were out skiing/camping in the Hyalite Lake area. Late Saturday afternoon we started skinning up towards Hyalite Peak. The path up to the ridge was super hardpacked and windswept. We got up and there was quite a bit of snow loaded above the north slope. I dropped over the side and took about two turns before the entire face above me released from the very top and traveled down the entire north side down to the bowl below. I was able to get to the rocks on the side and my partner was able to pick his way down. The crown looked a few feet deep from what I could see and stretched across the entire top of the line.
Me and a buddy were out skiing/camping in the Hyalite Lake area. Late Saturday afternoon we started skinning up towards Hyalite Peak. The path up to the ridge was super hardpacked and windswept. We got up and there was quite a bit of snow loaded above the north slope. I dropped over the side and took about two turns before the entire face above me released from the very top and traveled down the entire north side down to the bowl below. I was able to get to the rocks on the side and my partner was able to pick his way down.