It was easy to crack the thin wind slabs that formed from strong wind the last 2 days. They were not propagating, but cracking indicated potential instability on wind drifts. Photo: GNFAC
Strong wind in the previous 2 days sculpted the snow surface into waves of sastrugi. Photo: GNFAC
Wind in the last 2 days gusted 45-70 mph and stripped some starting zones down to dirt in Beehive Basin. Photo: GNFAC
Skier triggered cornice failure avalanche. Broke at skis 10-12 feet from the lip. No one caught or injured. Full snow profile from a couple hundred feet down the ridge on a similar ESE aspect. Coordinates in this entry are to cornice failure. Coordinates listed in snow profile are to pit location. Please don’t include the photo of snow profile in any posting. I have a video that I am unable to upload here. Please feel free to reach out with any questions or if you have another way I can send you the video. Thank you.
Beautiful day on Ellis with the classic Ellis snow pack, i.e., shallow, depth hoar, no supporting base. Snow pit at top of the burn, 85 cm depth. Depth hoar at ground up to 10-15 cm, smaller grain size above. ECTX. The column under the shovel blade failed completely at 25 hits in compression, no shear plane. We experienced no signs of snow instability. Skied one run down the burn being light on skis, then skied out via our super secret exit route in the trees where the skiing was not any better until lower on the mountain. Moonshine trail was super fast with the added obstacle of people HIKING up (another attribute of the New Bozeman).
Question for Ian. For your recent post from Ellis did you ascend/descend via saddle between Big and Little Ellis? Just curious.
<p>Since Friday morning the mountains near Cooke City got nearly 2.5 feet of snow (2.8” of <strong><a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314… water equivalent</a></strong>) along with strong southerly winds. Dangerous avalanche conditions exist, and human triggered avalanches are likely on steep slopes. Snow and strong wind ended yesterday. Natural avalanches are less likely, but possible on slopes that continue to get wind-loaded today. Yesterday we received reports of a couple natural avalanches that broke on wind-loaded slopes during the storm (<strong><a href="https://www.mtavalanche.com/images/22/natural-near-lulu-pass-north-scot…;, <strong><a href="https://www.mtavalanche.com/images/22/natural-avalanche-republic-crk">p…;). On Friday a rider triggered a 2 ft deep slide that broke 100 ft wide while digging out his stuck sled, thankfully he is okay (<a href="https://www.mtavalanche.com/node/25432"><strong>details</strong></a>). Today avalanches can be triggered 2-3 feet deep in the recent snow, and it remains possible to trigger a much larger avalanche that breaks on weak snow near the bottom of the snowpack. The snowpack needs more time to adjust to the recent heavy storm. Avoid travel on and underneath slopes steeper than 30 degrees. Today the avalanche danger is CONSIDERABLE.</p>
<p>Strong wind over the last week drifted new snow into slabs that can avalanche under the weight of a skier of rider. Avalanches can fail on a weak layer of small facets that was buried by the recent new and wind-drifted snow. Yesterday skiers in Beehive Basin and on Mt. Blackmore in Hyalite found this weak layer buried 1-2 feet down. They got unstable results in their snowpack tests and chose to ride low angle terrain. Avalanches could also break deeper in the snowpack on weak layers near the ground, particularly near West Yellowstone and in the southern Madison and southern Gallatin ranges where more snow fell last week and we saw activity on deeper layers earlier this season.</p>
<p>Careful snowpack assessment is essential before riding on steep slopes. Be cautious of fresh drifts and be certain there are no potentially unstable buried weak layers. Human triggered avalanches are possible, and the avalanche danger is MODERATE.</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>
The West Yellowstone Beacon Park is up and running! Stop by to check it out and practice with your rescue gear.
See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:
From obs: 1/8/21: "...One minor avalanche observed in Republic Creek. It was on a steep and rocky E, NE aspect around 9700'..."
