23-24
Natural avalanche on East Henderson
Natural avalanche on East Side of Henderson Mtn. seen late on 2/7/24. South of the two that Doug saw last week, along the ridge. Could have happened yesterday or last night. I didn’t see it yesterday when riding up and down Fisher creek, but visibility was mediocre. The debris and bed had at least some new snow on it.
Also had a large rumbling collapse near 10,000’ west facing when following one skiers old skin track. And had a few large collapses on south facing slopes between 8,000-9000’.
Large Avalanche Tepee Basin
From FB Messenger and phone conversation: A group (group 1) of sledders in the meadows of Tepee Basin witnessed an avalanche that failed an estimated 4 feet deep and up to one mile wide of the NE-facing wall that makes up the perimeter of Tepee Basin. They described the avalanche as breaking across the entire face, which, measured on Google Earth, is over a mile wide.
A second group (group 2) was riding higher in the meadow. We suspect that group remotely triggered the avalanche.
Group 1 confirmed that group 2 was clear and they got out their beacons to confirm no one else was captured.
From FB Messenger (second group): "The whole skyline ridge went off this afternoon on the Tepee side. We may have triggered it with our tree riding below, but the whole thing let go about a mile wide."
Video overview: O. El-Zaru
Collapsing Henderson Mt., Cooke City
From email: "Breaking trail, we experienced at least 20 collapses, several of which were large enough to knock snow off the trees around us. Above 9200’ where the snowpack started to deepen, we did not get any collapses or cracking. "
Henderson Mountain Observations
From email: "My friend and I toured in Cooke City today. We skied the low angle glades on the South side of Henderson Mountain. Breaking trail, we experienced at least 20 collapses, several of which were large enough to knock snow off the trees around us. Above 9200’ where the snowpack started to deepen, we did not get any collapses or cracking. We dug a quick pit at 9750’ on a SSE aspect. The site we dug on had been wind loaded substantially before the high pressure cycle last week. Skies were mostly cloudy with the sun poking out occasionally, light winds out of the west. Our ECT did not have propagation, but the results from our CT test were poor. Given the sketchy conditions, we stuck to low angle terrain."
Shooting Cracks, Hyalite
While ski-cutting a slope skiers saw cracking on the slope. This slope did not avalanche.
New Snow in Taylor Fork
We rode into Taylor Fork today 02/07/2024. We found 12" of new snow that has fallen over the last few days. This new snow fell onto a very weak snowpack and our stability tests yielded poor results, ECTP 14 on a south-facing slope at 9200'. Southern aspects have a stout 2" crust that formed from last week's warm temperatures, over weak faceted snow. This is where we saw failure in our stability tests.
With poor visibility, we were not able to see any recent avalanche activity. However, we know the recipe is there. A uniformly weak snowpack has received a large amount of snow pushing it to the edge. Getting on or below terrain steeper than 30 degrees is not recommended.
Low clouds moved in by early afternoon and the wind was steady and moderate from the southwest. No new snow fell while we rode today.
Fractured slope in hyalite
Skied a northeast face that was around 35-40 degrees at around 9000 ft. Entire slope fractured on second ski cut but did not slide. A dusting of new snow, with a good bit of powder on the ground.
Poor Stability on ECT in Beehive Basin
Persistent Problem visible
isolated shooting cracks and some roller balls observed