From obs: "My partner and I were traveling along the ridgeline separating Beehive and Middle Basin. 60 meters before the prayer flags on the ridge, we were stomping on the cornices. We heard a very loud whumphf and the cornice directly below me fell. This and our stomping triggered shooting cracks along the ridge and remotely triggered a cornice 30 meters ahead of us. This cornice fall triggered a hard slab avalanche that was about 15 meters wide and ran at least 100 hundred meters, but we could not see the terminus in the trees. The crown was 1F wind slab failing on facets 35 cm deep.
23-24
Cracks and Whumpfs in Tele Meadows
From obs: "Snowpack was 5-8” of wetter snow on top of the old facet layer.
Every time we stepped away from the skin track or skied untracked snow heard a few whumpfs and saw shooting cracks (most in the few foot range but a few extended 40-50’ across the slope). "
Collapsing and Cracking Hyalite Peak
From obs: "Continued up towards Hyalite. Consistent whumphing when breaking trail. Consistent beefy storm slab underneath 4-5” of fresh snow once out of the thick trees. Snow so unsupportive we couldn’t walk 15 feet to dig our pit. We also observed signs of recent natural avalanche activity in Divide Basin"
Natural Avalanches on Mt. Blackmore
Skiers in Hyalite saw an avalanche near the top of Mt. Blackmore that likely happened early on 01/20 or late on 01/19. Additionally, they saw more recent natural activity on the west side of the mountain.
Skiers saw a recent natural avalanche on the west side of Mt. Blackmore. Photo: S. Lowe
From obs: "The crown of the westward slide looked to be around 4'. Like the one reported the other day, it ran almost to the skin track. Winds were high in the basin and on the ridge tops, transporting snow into moderately stiff slabs." Photo: S. Lowe
A natural avalanche to the lookers left of the summit of Mt. Blackmore.
From obs: "I noticed new debris coming out of the lookers left chute on Southeast face of Blackmore. got closer to the ridge and noticed this. happened last night or this morning. 5 feet deep 50 to 100 ft wide and ran roughly 800 feet."
Photo: N. English
Forecast link: GNFAC Avalanche Forecast for Sun Jan 21, 2024
Avalanche triggered on 01/19. From obs on 01/20: "Off the top on the face of Blackmore- Talked to the guy that set this slide off, it was triggered while he was skiing down yesterday (01/19) morning from the summit. Ran all the way down to almost the skin track." Photo: N. English
Unstable hard slab in the Bridgers, and two collapses
Toured up the Ramp in the Bridger Range. At the top of The Ramp/Wolverine I pushed on some small wind-loaded terrain features with skis. About three inches of soft snow moved/cracked no wider than my ski width, then one step lower a hard slab cracked out about 10' wide, 10-12" deep and did not move more than a few inches downhill due to flatter terrain supporting it below. The slab was pencil hardness which leads me to believe it was older than the last snowfall on Wed-Thurs, but possible it formed during that event if there was a period of moderate-strong wind at the ridge.
I had two other terrain-feature sized "whumphs" on similar small wind-loaded slopes directly adjacent. These hard slabs were sitting on sugary facets, and show that avalanches can be triggered on previously wind-loaded slopes.
Forecast link: GNFAC Avalanche Forecast for Sun Jan 21, 2024