From obs 12/3/22: "Looking toward Ernie Miller ridge, we noted an old crown in the main bowl just below the summit. It was on an E-NE aspect, 200 or more feet wide and looked to be filled in with new snow but was still visible." Photo: H.Darby
22-23
From obs 12/3/22: "Toured up to Bacon Rind today and skied meadows off of the ridge. Dug a pit at 8700' on a W aspect. HS was 70cm. We got an ECTP12 45 cm up from the ground at the interface between wind packed snow and a layer of .5-1mm facets and mixed forms. That layer made up the bottom 45cm of the snowpack in that area. Dug another pit at 8800' on an E aspect. HS was 115cm. We got an ECTP 14 50cm up from the ground on that same interface as described above. The bottom 50cm of the snowpack looked to be facets and mixed forms.
From obs 12/3/22: "Toured up to Bacon Rind today and skied meadows off of the ridge. Dug a pit at 8700' on a W aspect. HS was 70cm. We got an ECTP12 45 cm up from the ground at the interface between wind packed snow and a layer of .5-1mm facets and mixed forms. That layer made up the bottom 45cm of the snowpack in that area. Dug another pit at 8800' on an E aspect. HS was 115cm. We got an ECTP 14 50cm up from the ground on that same interface as described above. The bottom 50cm of the snowpack looked to be facets and mixed forms.
Collapsing on Ernie Miller Ridge
"We toured to Ernie Miller today and saw a natural avalanche on a NE slope around 9600 ft. We heard and felt multiple collapses on our way in. We dug a pit on an east facing slope around 9300 ft where we found 105 cm of snow. We got a ECTN 2 result, failing on an interface about 15cm from the surface and ECTP5 failing 40 cm from the surface."
"Toured up to Bacon Rind today and skied meadows off of the ridge. Noted many collapses and whumpfs in the snowpack as we ascended east aspects to the ridge."
GNFAC Avalanche Forecast for Sun Dec 4, 2022
<p><span><span><span><span><span><span>Yesterday morning riders reported a large natural avalanche on Lionhead Ridge that occurred the prior night (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27046"><span><span><span><strong><span… and details</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Wednesday through Friday, the mountains received over two feet of snow accompanied by strong winds which caused large avalanches to break naturally on Thursday through early yesterday (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27021"><span><span><span><strong><span…;). Recent natural avalanches indicate buried persistent weak layers were pushed to their breaking point, and today human-triggered avalanches remain likely. Dangerous avalanche conditions exist and avalanche danger is CONSIDERABLE. Cautious route finding and conservative terrain selection are essential.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Between Wednesday and Friday over two feet of snow fell accompanied by strong winds. This rapid addition of weight to the snowpack created large, 3-4 foot deep natural avalanches on all aspects (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27013"><span><span><span><strong><span… and photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). With clear skies yesterday, riders saw natural avalanches on </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><strong><span><span> </span></span></strong></span></span></span><span><span><span><span><span><span>and </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> that likely broke Friday morning. I was riding near Cooke City two days ago and found buried weak layers that I suspect contributed to recent avalanche activity (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=p4oOrj6x7oU&list=PLXu5151nmAvTi1DBS… from Friday</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). The likelihood of triggering a large avalanche has decreased, but the consequences are high. Large, human-triggered avalanches are possible and danger is MODERATE. Danger may increase this afternoon if snowfall is heavy.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Six inches to a foot of snow fell on Thursday and Friday, and strong wind drifted this snow into thicker slabs. These wind slabs are possible to trigger, especially where they formed on top of buried weak layers (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=aqqdf5N85DM&list=PLXu5151nmAvTi1DBS… Fork video</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/27037"><span><span><span><strong><span… Rind observation</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Snow and wind this afternoon may create fresh, unstable wind slabs. Be cautious of drifts of snow on steep slopes and dig down to check for buried weak layers before riding steep slopes. Human-triggered avalanches are possible and the avalanche danger is 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>
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Observed 12/3/22. Photo: Z. Peterson
Forecast link: GNFAC Avalanche Forecast for Sun Dec 4, 2022
From IG 12/3: "...Most notable was this massive slide on fox, looks to have broke 2-6’ deep and over 1000’ wide. Couldn’t quite see the toe from our tour but it looked to have run over 1000’ vertical. Never have seen one so large on Fox…" Photo: M. Cohen
Forecast link: GNFAC Avalanche Forecast for Sun Dec 4, 2022GNFAC Avalanche Forecast for Mon Dec 5, 2022
Large Natural on Lionhead, Airplane Bowl
From IG 12/3: It was natural. Happened last night or this morning. It hadn't slid when we left yesterday. We were first tracks in today, and there were no tracks above or below this slide. Crown at the peak was around 6'. Average 2-3' crown. 10' debris piles at least.
From IG 12/3: "It was natural. Happened last night or this morning. It hadn't slid when we left yesterday. We were first tracks in today, and there were no tracks above or below this slide. Crown at the peak was around 6'. Average 2-3' crown. 10' debris piles at least." Photo: R. Malmstrom
Forecast link: GNFAC Avalanche Forecast for Sun Dec 4, 2022
From IG 12/3: "It was natural. Happened last night or this morning. It hadn't slid when we left yesterday. We were first tracks in today, and there were no tracks above or below this slide. Crown at the peak was around 6'. Average 2-3' crown. 10' debris piles at least." Photo: R. Malmstrom
Forecast link: GNFAC Avalanche Forecast for Sun Dec 4, 2022GNFAC Avalanche Forecast for Mon Dec 5, 2022