Avalanche in 2nd Yellowmule. Likely broke during storm on 12/24. Less than a foot deep but ~150 ft wide. Photo: GNFAC
Skiers reported: "Two new [trigger unknown] avalanches on the east side of Henderson today. The first photo is from this morning (12/27/19) around 11:00. The second one appears to be much deeper and I didn't notice it until I rode back by around 2:30, so it might have occurred while I was out skiing or I just missed it this morning."
From Dave and Doug's investigation on 29 Dec:
1. The lookers left avalanche was the deepest at 6' deep of Hard Slab. Estimated 150' wide and 300' vertical. It broke on facets near the ground.
2. The avalanche to the right was 3' deep and also broke on facets near the ground. It too was heavily wind-loaded. Estimated 250' wide and 300' vertical.
Skiers reported: "Two new [trigger unknown] avalanches on the east side of Henderson today. The first photo is from this morning (12/27/19) around 11:00. The second one appears to be much deeper and I didn't notice it until I rode back by around 2:30, so it might have occurred while I was out skiing or I just missed it this morning." Photo: H. Coppolillo
Skiers reported: "Two new [trigger unknown] avalanches on the east side of Henderson today. The first photo is from this morning (12/27/19) around 11:00. The second one appears to be much deeper and I didn't notice it until I rode back by around 2:30, so it might have occurred while I was out skiing or I just missed it this morning." Photo: H. Coppolillo
From email (12/26): "Saw some recent avalanche activity on steep east facing wind loaded slopes of Henderson and Sheep. Both avalanches looked recent and were "pockets" going in the D2, R1.5 range about 1.5-2.5' deep."
<p>The snowpack has now had a couple days to adjust to the weight of the new snow (7-10”) that fell earlier in the week. However, with a weak faceted foundation, it will take a bit more time before the snowpack can be trusted.</p>
<p>Yesterday, Alex and I went to the Lionhead area to see how the snowpack had dealt with the load of new snow (<strong><a href="https://www.youtube.com/watch?v=kuqUUzl0Wj8&list=PLXu5151nmAvSbcbVf…;). We saw limited avalanche activity and had no cracking or collapsing. This lines up with similar reports from skiers and riders in the Madison Range. These are promising signs looking forward, but don’t change the big picture: the snowpack just got loaded and has a weak base. Triggering avalanches breaking near the ground remains a real possibility. Give it a couple more days before getting onto steep terrain. The avalanches danger is MODERATE.</p>
<p>Yesterday, skiers saw recent avalanches on steep, east facing, wind loaded slopes off Henderson and Sheep Mountains. Triggering avalanches is possible today, both directly beneath the new snow on windloaded slopes or on weak layers buried 1-2 ft deep. These weak layers have shown themselves to be most problematic on slopes where there are crusts around them. Adopt a two-pronged approach to deal with these concerns: dig to look for the weak layers and simply steer around the most drifted slopes to give them a little more time to settle. The avalanche danger is rated MODERATE.</p>
<p>The couple inches of new snow that fell this week gave the snow surface a nice refresh, but haven’t significantly impacted the avalanche conditions. The snowpack is generally stable. Still, normal caution is required. Watch for isolated wind drifts near ridgelines where you might be able to trigger a small slide. Always carry your rescue gear (beacon, shovel, probe) and only expose one person at a time to steep slopes. For today, the avalanche danger is rated LOW.</p>
<p>If you get out, please send us your observations no matter how brief. You can fill out an <strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong>, email us (<strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong>), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>
Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.
COOKE CITY
Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.
WEST YELLOWSTONE
