ECTP 10, 15 cm slab breaking approximately 15 cm beneath new snow. East facing leeward slope. Approx 45.525, -110.952 elevation 7696. Surface hoar present on all slopes, approximately bottom 30 cm sugary facets.
From obs: "While ski touring in the Hyalite Creek Drainage today, my ski partner and I both, at separate times of the day, remote triggered sudden collapses. Each time, we felt the snow collapse underneath our feet, and then heard and felt a deep "whumph". The noise came from the North of us both times, where the slope was slightly steeper (still below about 28 degrees-- not colored with "slope angle shading" layer on caltopo.)."
While ski touring in the Hyalite Creek Drainage today, my ski partner and I both, at separate times of the day, remote triggered sudden collapses. Each time, we felt the snow collapse underneath our feet, and then heard and felt a deep "whumph". The noise came from the North of us both times, where the slope was slightly steeper (still below about 28 degrees-- not colored with "slope angle shading" layer on caltopo. The danger was rated as "moderate" in the Northern Gallatins today, so we were both extremely surprised by these events.
I am also wondering if you have any women on your team, or if you are just "The Avalanche Guys"?
Thanks so much for all that you do.
From email: "Got up to Blackmore way. I didn’t like the skin track heading up to N ridge but my partner was a little ahead and should of reeled him back... because the main skinner right now is exposed to much of face. So when caught up we angle lookers right a tidge to gain ridge. Just before the ridge was the disturbing collapse."
Skiers triggered this avalanche on Flanders Mountain on 1/9/21. It was triggered out of the photo to the right on a seperate slope around the corner. It propagated over 1000' wide, and looks to be 6' deep at deepest. Photo: A. Blackmer
Skiers triggered this avalanche on Flanders Mountain on 1/9/21. It propagated around the corner over 1000' wide into an adjacent path.
From obs: "We dug a pit and found a really weak snowpack! Regardless of the poor stability result, we proceeded to ski an East facing bowl south of Flanders Mountain knowing that the slope angle was low and only flirted with 30 degrees in some parts of the bowl. We could have chosen to ski the trees further to our left, but after evaluating the consequence associated with skiing the bowl, we decided that the center of the bowl did not pose too big a risk given we skied one at a time. My partner skied first, he skied practically all the way back to the skin track when the slope failed and the entire bowl released. He was pretty well out of the way of danger by the time the bowl began to move. From our perspective, the trigger happened at the bottom of the slope.... The bowl was not the only slope that slid, the avalanche propagated around the ridge and released a slide on the more south-easterly facing aspect just south of the bowl. We tail-tucked and went home glad no one was caught or hurt."
GNFAC forecasters visited the site on 1/11/21. We measured the maximum slope angle in the start zone at 35 degrees with an average slope angle of 33 degrees. The debris in each path was up to 2-3 meters deep. The avalanche broke on a layer of weak faceted snow 70 cm above the ground, and propagated almost 1000 feet wide. The crown was 2-3 feet deep.
From obs: "We dug a pit and found a really weak snowpack! Regardless of the poor stability result, we proceeded to ski an East facing bowl south of Flanders Mountain knowing that the slope angle was low and only flirted with 30 degrees in some parts of the bowl.... My partner skied first, he skied practically all the way back to the skin track when the slope failed and the entire bowl released. He was pretty well out of the way of danger by the time the bowl began to move. From our perspective, the trigger happened at the bottom of the slope.
