Saw this crown from a distance today. Possibly natural R3-D3 on ESE aspect, likely caused by wind loading. Unsure when it occurred, but crown looked large and debris ran into the flats mowing down some small flag trees.
Two large, widely propagation fractures visible through a hole in the cloud cover Monday A.M. from Bridger Canyon Dr. Upper slab failure evidently stepped down to a deeper layer estimated 400' below upper crown. Both crowns appeared to be similar depth. Also visible were debris toes further to the North that had run mostly full path. Looked like it was already covered up yesterday (tues).
A second ob via phone message:
A large natural avalanche occurred on the north summit of Bridger Peak yesterday (Monday, 27 March). The crown line was complex.
Two large, widely propagation fractures visible through a hole in the cloud cover Monday A.M. from Bridger Canyon Dr. Upper slab failure evidently stepped down to a deeper layer estimated 400' below upper crown. Both crowns appeared to be similar depth. Also visible were debris toes further to the North that had run mostly full path. Looked like it was already covered up yesterday (tues).
Via phone message:
A large natural avalanche occurred on the north summit of Bridger Peak yesterday (Monday, 27 March). The crown line was complex.
We rode into the Throne from battle ridge and skinned up the east face. We saw three new snow avalanches (previously reported) on the SE and E faces of the Throne where we parked the sleds. Surface crusts are quite variable depending on slope angle, aspect, and shading from trees. The crust was generally present and breakable on the SE and E aspects we traveled on. We dug a quick pit on at the base of the E face. ECTP16 on 1 mm facets underneath last weekends snow. We measured 50 cm (20") of new snow with 2" snow water equilavent. Dug again in the crown of one of the slides. The new snow had consolidated a bit because of a more southerly aspect (~16" deep), but there was also 2" of SWE in the crown. Slide broke on small facets above a firm crust. The slides all appear to have run mid storm or just as it was ending. One of the slides was clearly skier triggered, the others are unknown.
The presence of facets under the new snow means that it'll take longer for that new snow to stabilize.
On a sunset tour we headed up to grab some low hanging fruit in the W Bridgers. We were shocked to find such a deep snowpack in the plains. Skiing a meadow off the valley floor from the North Cottonwood Canyon TH, we dug a pit at an elevation of approx. 5,800ft on a west aspect. The snowpack was 85cm deep, with this weekends new snowfall making up the top 45cm, the sun had affected the top 5cm creating a thin warmer layer and then surface crust as temperatures dropped. The bottom 40cm was a melted down, 4F hardness layer of weaker snow to the ground. At the moment the new snow appeared to be bonding well to the previous snowpack but it was very visible that this bottom layer was trending towards faceting and weakness. Our test result was ECTN 14. There was no breakage into the weak snow below the new snow. We skied a beautiful 25-30 degree pitch into the setting sun.
We observed evidence a couple of recent slab avalanches at the throne
We observed evidence of a couple of recent slab avalanches at the throne. Photo: J. Weingarten
