Photos

This big natural avalanche broke late on 1/17/20 or early 1/18/20 after strong wind and new snow (1" SWE) heavily loaded slopes. Photo: GNFAC

Natural avalanche observed on 1/17 in Airplane Bowl off of Lionhead Ridge.

Photo: P. Smith

Natural avalanche on 1/16 near Hardscrabble Peak in the Northern Bridgers.

From observation: "At some point between 12:00 and 15:00 a large natural slide occurred in 'October Bowl'. My partner and I saw no tracks in the area. We witnessed a large amount of snow being deposited on that aspect throughout the day. In the photos you can see the crown from 01/16 and the new crown up and to the right."

Photo: R. Griffiths

Natural avalanche on 1/17 near Hardscrabble Peak in the Northern Bridgers.

From observation: "At some point between 12:00 and 15:00 a large natural slide occurred in 'October Bowl'. My partner and I saw no tracks in the area. We witnessed a large amount of snow being deposited on that aspect throughout the day. In the photos you can see the crown from 01/16 and the new crown up and to the right."

Photo: R. Griffiths

A small but relatively deep avalanche triggered by a snowmobiler on Tuesday, 1/14/2020. 30 ft wide. Ran 20 vertical feet. This avalanche broke to 2-3 ft deep, to the ground. This is the second time this year this slope has slide, it also avalanched in mid-December. Photo: GNFAC

"... while touring in the Northern Bridgers, my partner and I noticed a very large avalanche that occurred on a North face in "October Bowl" just to the south of Hardscrabble Pk. We didn't witness it and are unsure of a trigger, but we came in contact with all parties believed to be out there and assume it occurred naturally early this morning from heavy wind-loading. The crown seemed to be 2-3' deep but stepped down to the ground about 200' below the crown. The slide was about 400' in width and ran about 1,000' and we assumed classifications of R3.5 and D3. Debris pile was expansive and deep, and prompted us to stick to Southern aspects."  Photo: McKinley Talty

"... while touring in the Northern Bridgers, my partner and I noticed a very large avalanche that occurred on a North face in "October Bowl" just to the south of Hardscrabble Pk. We didn't witness it and are unsure of a trigger, but we came in contact with all parties believed to be out there and assume it occurred naturally early this morning from heavy wind-loading. The crown seemed to be 2-3' deep but stepped down to the ground about 200' below the crown. The slide was about 400' in width and ran about 1,000' and we assumed classifications of R3.5 and D3. Debris pile was expansive and deep, and prompted us to stick to Southern aspects."  Photo: McKinley Talty

This is the smaller of two avalanches that occurred on Thursday (1/16/20) on Henderson Mountain near Cooke City. It is believed to have been triggered by snowmobilers. Photo: B. Whittle

This avalanche occurred on Thursday (1/16/20) on Henderson Mountain near Cooke City. It is believed to have been triggered by snowmobilers. Photo: B. Whittle

This avalanche occurred on Thursday (1/16/20) on Henderson Mountain near Cooke City. It is believed to have been triggered by snowmobilers. Photo: B. Whittle

From an email:

From afar, observed a large R4/5 D3, to the ground, off of the entire NE shoulder of Fox Mtn. (see attached photo) as well as a couple of scattered R1/D1 wind slabs on upper elevations on E/NE aspects. 

From an observation:

Once in the bottom of Bear Basin, we could see a much larger avalanche that looked to be 1-2 days old. Its disjointed crown was some 150ft wide, but it was hard to tell how deep it was, as its crown was fairly far away and partly blown back in. Parts of the slide ran on the ground layer of facets but looked to be the result of wind load. Photo: C. Kussmaul

From an observation:

Once in the bottom of Bear Basin, we could see a much larger avalanche that looked to be 1-2 days old. Its disjointed crown was some 150ft wide, but it was hard to tell how deep it was, as its crown was fairly far away and partly blown back in. Parts of the slide ran on the ground layer of facets but looked to be the result of wind load. Photo: C. Kussmaul

From e-mail: "Skiers triggered two separate slides on south Saddle this afternoon. we witnessed the smaller slide to the lookers right of the big slide, the bigger one happened later apparently... The first smaller slide was caused by a ski cut near the trees, fracture was about 2 feet, soft slab that seemed to run on a thin sun crust. below the sun crust was also very weak and sugary. Not sure when the second skier went farther out and triggered the whole bowl, but they got lucky!!" Photo: T. Andersen

From e-mail: "Skiers triggered two separate slides on south Saddle this afternoon. we witnessed the smaller slide to the lookers right of the big slide, the bigger one happened later apparently... The first smaller slide was caused by a ski cut near the trees, fracture was about 2 feet, soft slab that seemed to run on a thin sun crust. below the sun crust was also very weak and sugary. Not sure when the second skier went farther out and triggered the whole bowl, but they got lucky!!" Photo: T. Andersen

Photo attached of a couple thin, natural slab avalanches near Cooke this morning (1/15/20).  SE aspects of Mineral Mtn., around 9,600'. Photo: B. Fredlund

Skier triggered avalanche in Argentina Bowl on Saddle Peak. Observed from the highway. Occurred during the day on Wednesday, 1/15/2020. Photo: GNFAC

The snowpack in Lionhead is a respectable 6' deep. The facets near the ground are gaining strength and we were unable to get them to break in our tests. Stability is improving! Photo: GNFAC

Small skier triggered loose dry avalanche observed on a south-facing slope at about 9000' on the ridge separating Beehive and Middle basins. Photo: C. Oshiro-Leavitt

We toured into Meridian today. On our approach we remote triggered a soft slab on the climber’s left (west) side of the crux approach slope. It was 50’ wide, ran 150’, and the crown was about 12-15”. It was a south aspect at 8370’ with a ~40 degree start zone. The storm slab ran on a crust. Photo: N Hance