Photos

From email: "Observed a fresh slab avalanche on Mt. Henderson this morning.  E, SE aspect, 9,900'... would estimate the size of the crown to be 2-4' deep and about 80' wide... Likely a natural avalanche (from about 36 hrs ago), but there were fresh sled tracks in the vicinity from yesterday, so possibly a remote trigger." Photo: B. Fredlund

Big Sky Ski Patrol intentionally ski cut an avalanche breaking on the weak snow near the ground during avalanche mitigation work on 12/8/23.

From email: "[An avalanche] released on a ski cut, breaking on facets above a basal crust, easterly aspect, just below tree line."

Photo: BSSP

From email:

"While grooming the xc trails in Beaver Creek drainage last night, I observed extensive cracking and collapsing in the 12"+ of new snow.  Essentially every slope above the trail would fail as I approached them, some breaking up to 30' away.  I know it's not a good sign but was cool to watch.  

7,5k'-7,9k' mostly North facing aspect.  

Yesterday's addition here was right side up with the initial snow coming in very wet and heavy, while ending in a light fluffy topping which is now getting blown around.  Additional trace overnight and currently snowing again at 8am. " Photo: J. Gerardi

From email:

"While grooming the xc trails in Beaver Creek drainage last night, I observed extensive cracking and collapsing in the 12"+ of new snow.  Essentially every slope above the trail would fail as I approached them, some breaking up to 30' away.  I know it's not a good sign but was cool to watch.  

7,5k'-7,9k' mostly North facing aspect.  

Yesterday's addition here was right side up with the initial snow coming in very wet and heavy, while ending in a light fluffy topping which is now getting blown around.  Additional trace overnight and currently snowing again at 8am. " Photo: J. Gerardi

From facebook message: "North facing slope 15 miles south of west Yellowstone probably 30ish degree slope. Probably 16-18 inch slab". Photo: T. Taubman

From obs: "Dug into the hillside right before going up the creek. Snow pack was 75 cm deep consisting of three layers. Bottom 35cm is obviously faceted, grain size is around 2mm. Very thin ice crust at around 35cm. Upper 35 cm of snow is brand new snow from this current storm, precipitation particles, low density, with minor wind effect. Performed a quick Compression Test and the ice crust layer failed on the second tap." Photo: S. Gralla

From obs: 

"On descent this new snow was touchy, and we observed 2 natural avalanches, max depth 15 cm, on the small end of size 1, F hardness, running less than 30-50m exclusively in new snow. (SS-N-R1D1-N)"

From obs: 

"On descent this new snow was touchy, and we observed 2 natural avalanches, max depth 15 cm, on the small end of size 1, F hardness, running less than 30-50m exclusively in new snow. (SS-N-R1D1-N)"

From obs: 

"On descent this new snow was touchy, and we observed 2 natural avalanches, max depth 15 cm, on the small end of size 1, F hardness, running less than 30-50m exclusively in new snow. (SS-N-R1D1-N)"

Natural avalanche in closed terrain at Big Sky Ski Resort on 12/7/23. Photo: BSSP

"A large natural slide came down from 3rd Fork, stepped down in the Elbow and again in the cone, and ran almost to the runout of Obsidian. Naturals came out of most of the Headwaters, with both Firehole and Hellroaring stepping down into old snow in the cones."

Skier triggered avalanche at the bottom of the 2nd/3rd finger at Bridger Bowl.

Big Sky Ski Patrol triggered hard slab avalanches during their avalanche mitigation work. Photo: BSSP

We rode up Daisy Pass road... saw a couple 8-10" deep natural avalanches on the steep slopes above Miller Creek that probably ran in the last 24-48hours. We had multiple collapses on the NE facing slope where we ski toured to dig our second pit. Photo: GNFAC

Constant red flags on W Henderson. 

From text message: "The attached picture is a little slide that went off when I was doing small turns on an adjacent slope. That's Beaver Slide! There was more small slides south in the trees. Heard whumphing here and there." Photo: J. Onken

From obs: "Lots of cracking and collapsing on skin track and ski cuts were reactive on steeper slopes. Dug on NE slope 9640'. HS 110cm ECTN 12 & ECTN 14 40cm down." Photo: R. Youngbar

Climbers in the Dribbles area of Hyalite Canyon collapsed a slab of wind-drifted snow resulting in a spider web of shooting cracks. Photo: Sam

Climbers in the Dribbles area of Hyalite Canyon collapsed a slab of wind-drifted snow resulting in a spider web of shooting cracks. Photo: Sam

From IG: “Skied in the lions head today on a northeast slope at 8,300 feet. Clear wind loading and reactive cornices, however storm snow was low energy with little movement. 10-14 inches of medium density snow. Whumpfing was noticed on all slopes on the eastern half of the compass.” Photo: O. Desroches

From obs: "Skinned above alpine lift (just beyond the beacon checker) to get an idea for snowpack depth/ layers. A quick dig revealed a shallow, faceted snowpack!"