Saw this crown the morning of 2/28 from G1 while climbing. Looks like it broke naturally within the past day or two
From obs: "Observed a small avalanche while teaching a rec. 1 today for MSU. The light was too flat to see a crown. Based on the light wind, ski patrol obs. and our moving obs., I hypothesize that it was a dry, loose avalanche. L-N-R1-D1.5-I."
Patrol reported: "A midday report from [a skier] that he had released the Duane's Cornice (out of bounds to the north) as he travelled to the ramp had us looking for any tracks below, none were observed. It looked to step down and pull some older layers as it went through the lower pinch."
<p>Yesterday’s snow favored the Bridger Range and West Yellowstone with 10-12” of snow equal to 0.7” of snow water equivalent (SWE). Elsewhere got 3-6” of snow equal to 0.3-0.5” of SWE. Wind increased last night and is drifting the new snow into fresh slabs. These slabs are easy for a rider or skier to trigger, and their additional weight increases the chances to trigger a deeper avalanche on weak, sugary snow near the ground. Yesterday I found this weak snow buried 3-4’ deep on Mt. Ellis (<strong><a href="https://www.mtavalanche.com/images/21/mt-ellis-weak-snow-ground">photo<…;, <strong><a href="https://www.mtavalanche.com/images/21/mt-ellis-n-ridge-profile-27-feb">… profile</a></strong>). It collapsed and propagated in most stability tests, but just knowing it exists on almost every slope was enough to avoid slopes steeper than 30 degrees. Avalanches on this layer are becoming more difficult to trigger, but they will be deep and wide, destructive, and potentially deadly (<a href="https://youtu.be/Ychm42ihtjk"><strong>Blackmore video</strong></a>, <a href="https://youtu.be/65JO-4w4qXo"><strong>McAtee Basin video</strong></a>).</p>
<p>Today fresh wind slabs are likely and will be larger where more new snow fell. Any amount of wind-loading with the weak snow buried deep in the snowpack is reason to step back to more conservative terrain selection. Avoid wind-loaded slopes, and remain extra cautious of all slopes steeper than 30 degrees. The avalanche danger is rated CONSIDERABLE on wind-loaded slopes and MODERATE on all other slopes.</p>
<p>Near Cooke City, weak snow near the ground is less widespread, but remains a concern in addition to avalanches breaking in recently drifted snow. Recent avalanche activity and signs of instability have been on either heavily wind-loaded slopes or slopes with a relatively shallower snowpack (5-6 feet). Slopes with both are the most unstable. A natural avalanche in Hayden Creek earlier in the week was on a wind-loaded slope that has avalanched several times already this year keeping the snowpack unusually thin and weak (<a href="https://www.mtavalanche.com/node/24432"><strong>details</strong></a>). Yesterday skiers in Republic Creek had unstable test scores (ECTP 30) on a weak layer buried 2.5 feet deep in a 5-6 foot deep snowpack. These conditions are not widespread, but are where avalanches are possible to trigger today. Assess for and avoid steep slopes that are heavily wind-loaded or suspect of having buried weak layers. Today, avalanches are possible to trigger and the avalanche danger is MODERATE.</p>
The Friends of the Avalanche Center in partnership with the City of Bozeman put in a Beacon Park at Beall Park. It is located on the north side of the Beall building between N. Bozeman Ave. and the ice rink. Stop by with your
On Mt Ellis (2/27/21) the snowpack has 20-40cm of depth hoar and facets at the bottom. Stability tests took a lot of force to collapse this layer, but it propagated (broke across the whole column) every time once initiated. This is a poor snowpack structure that makes large avalanche possible to trigger if you hit the wrong spot on a slope. Photo: GNFAC
Photos sent to us on 2/27/21 of recent activity south of Livingston. Photo: D. Britt
Photos sent to us on 2/27/21 of recent activity south of Livingston. Photo: D. Britt
135-145 cm HS and very supportable in the upper meadows. Thinner and less supportable at lower elevations and on approach. Dug a quick pit and did 2 ECTs in the east-facing low-gnar zone. ECTN teens in the layers of recent snow. ECTN upper 20s on the F+/ 4F- DH at the base of the snowpack. There is a 1m slab of (F-->1F) sitting on top of the facets.
Skied 30 degrees and under. Seemed like you would most likely get away with skiing steeper, but I wouldn't want to be the guy to test that theory based on structure. The weak layer is still accessible for a skier or rider.
Top-notch powder skiing today.
DZ
