From IG: “Ski cut trigger. West facing. 9800ft. Big sky area.” I. Freeland
22-23
Ski Triggered Avalanche
From IG: “Ski cut trigger. West facing. 9800ft. Big sky area.”
Natural Avalanche, 2nd Yellowmule
We rode through First and Second Yellowmule at Buck Ridge. There was a natural avalanche below the cornice line on the headwall above second Yellowmule that broke within the last 12 hours as it was not covered by any new snow. From a distance, it looked ~200' wide and broke 1-3' deep. I believe it failed under the storm snow, not of deeper weak layers.
Natural Avalanches, Bridger Range
From Marienthal Observation: "Drove up to Bridger at noon and saw a large avalanche on along the road north of the fire station. It was 75’ wide, 1-1.5’ deep and 25’ vertical. HS-N-R4-D1.5/2. It was on an east facing slope, south of the long slope that has cornices. The slope with cornices hadn’t slid at this point. On the way home at 3:30 the larger slope with cornices had slid. It was very big, possibly R5. 1.5-2’ deep, 200’ wide, huge chunks of hard slab and cornice. Looks like new wind-loaded snow with some gouges into older snow.
From Olson creek I had a cloud-free flat light view of the ridge from Saddle to Bridger Peak and looked with binoculars. There was a wind slab just north of quarter saddle that did not go over the cliffs. Probably 1-2’ deep, 30’ wide of new snow. There was a large wind slab on the north half of Between the Peaks (250’ wide) and one similar depth wind slab in the Pinnacles (100’ wide). Both of these broke 1-3’ deep immediately below the cornice and did not entrain much snow or propagate very wide or downslope given how much new snow there was. I could see the debris from the slide between the peaks which ran over 1000’ vertical to the top of the runout zone but relatively low volume."
From email, "At 12:45 I saw Climax run naturally. SS-N-R2-D2-I. The low visibility and distance made it hard to tell how deep the crown was, but based on there not being much volume of debris and it not running very far, I’m guessing it was within the new snow/storm interface and didn’t step down to any buried PWL.
In the photo, the red shows the approximate crown line, blue shows debris."
Climax Path, Natural Avalanche
From email, "At 12:45 p.m. I saw Climax run naturally. SS-N-R2-D2-I. The low visibility and distance made it hard to tell how deep the crown was, but based on there not being much volume of debris and it not running very far I’m guessing it was within the new snow/storm interface and didn’t step down to any buried PWL."
Natural Avalanche, Wall Mountain
Residents of Silver-Gate caught a glimpse of a large natural avalanche south of Silver Gate on Wall Mountain. The size is uncertain, but it knocked down a stand of trees. Two people state that they believe they heard the avalanche in the pre-dawn hours.
Drove up to Bridger at noon and saw a large avalanche on along the road north of the fire station. It was 75’ wide, 1-1.5’ deep and 25’ vertical. HS-N-R4-D1.5/2. It was on an east facing slope, south of the long slope that has cornices. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Tue Feb 21, 2023
Drove up to Bridger at noon and saw a large avalanche on along the road north of the fire station... The slope with cornices hadn’t slid at this point. On the way home at 3:30 the larger slope with cornices had slid. It was very big, possibly R5. 1.5-2’ deep, 200’ wide, huge chunks of hard slab and cornice. Looks like new wind-loaded snow with some gouges into older snow. Photo: GNFAC
Drove up to Bridger at noon and saw a large avalanche on along the road north of the fire station... The slope with cornices hadn’t slid at this point. On the way home at 3:30 the larger slope with cornices had slid. It was very big, possibly R5. 1.5-2’ deep, 200’ wide, huge chunks of hard slab and cornice. Looks like new wind-loaded snow with some gouges into older snow. Photo: GNFAC