Regional Conditions for Southern Madison

On Friday (12/13) there were natural avalanche crowns in Carrot Basin of Taylor Fork. These were a few days old, but show the potential to trigger slides on a buried persistent weak layer. Photo: GNFAC

On Friday (12/13) there were natural avalanche crowns in Carrot Basin of Taylor Fork. These were a few days old, but show the potential to trigger slides on a buried persistent weak layer. Photo: GNFAC

On Friday (12/13) we rode into Taylor Fork and found a weak foundation of the snowpack, Recent snow has created unstable conditions. Our stability tests showed unstable results on two weak layers. Photo: GNFAC

Skiers at Targhee Pass near West Yellowstone reported: "We got a few good collapses while skinning up through east-facing low angle meadows, and got some serious cracking and collapsing while stomping on fresh wind pillows just below ridgeline on a northeast-facing slope at about 8200'. We dug down at one of the cracks and found a 35cm thick F+ slab that had failed on a layer of 4-6mm depth hoar. Cracks propagated close to 100'..." Photo: A. Schauer

Riders reported multiple natural slab avalanches on N facing slopes. Photo: R. Rustigian

Riders reported multiple natural slab avalanches on N facing slopes. Note widespread crowns along slope in background. Photo: R. Rustigian

This natural avalanche on the northeast side of Crown Butte near Daisy Pass (Cooke City) almost caught people below. Approximately 2 feet of snow has fallen with wind and the avalanche danger is rated CONSIDERABLE. Photo: B. Whittle

Photo taken 12/6 near Two Top, south of West Yellowstone.

From email: "South facing stuff was thinner than I expected and north and west facing was a lot better than I expected. South facing stuff was 59cm deep and we had multiple ECT-P 14’s between the facets at the bottom and the newer snow."

Photo: B. Radecky

We sledded into Buck Ridge (12/4/2019) for the first time this season. The riding was supportable and soft, but we sank to the ground when we stepped off our sleds. This poor snowpack structure makes avalanches possible to trigger, and will create bad avalanche conditions when more snow loads on top. Enjoy the powder in low angle terrain. Photo: GNFAC

This is a close-up of the angular Depth Hoar grains found near the ground in the mountains south of Big Sky to West Yellowstone. These are weak and cannot support a lot of snow weight. Avalanches will break near the ground on these. Photo: GNFAC

At the bottom of the snowpack is a thick layer of weak and sugary, faceted snow called Depth Hoar. These large grains do not bond well and form an unstable foundation of the snowpack. Avalanches will break at this layer. Photo: GNFAC

We put up the Taylor Fork weather station today (12/03) and it is churning out hourly data. Check it out here: https://www.mtavalanche.com/weather/stations/taylor-fork

We partnered with the Gallatin Valley Snowmobile Association to put in two new beacon checkers at the Taylor Fork and Buck Ridge trailheads. They are working great!

Thanks GVSA! Photo: GNFAC

We recognize that backcountry skiing can be daunting to approach. That’s why Ben Goertzen and the Friends of the Gallatin National Forest Avalanche Center have teamed up to help breakdown some of the most prominent barriers of entry to backcountry skiing through this campaign. One lucky winner will be given a complete backcountry skiing kit, a spot in an avalanche awareness course, and featured in a three part video series that ends with an excursion into the backcountry with professional skier and filmmaker, Ben Goertzen . These videos will be used by the Friends of GNFAC to help other aspiring backcountry skiers gain awareness, knowledge and start to breakdown their barriers to entry.

Click Here for More Details on How to Enter

Watch the Backcountry Barriers Launch Video: https://vimeo.com/376473804

These small crowns indicate that new snow may not bond well to the old snow surface. Photo: B. Fredlund

Sometime last week (11/20-11/22) these large avalanches occurred on heavily wind loaded northeast facing slopes in the Absaroka. The snowpack there is thin and faceted, similar to the southern ranges and mountains near West Yellowstone. Photo: B. VandenBos

Sometime last week (11/20-11/22) these large avalanches occurred on heavily wind loaded northeast facing slopes in the Absaroka. The snowpack there is thin and faceted, similar to the southern ranges and mountains near West Yellowstone. Photo: B. VandenBos

Strong winds found snow to transport on Saturday 11/23. Photo: B. VandenBos

From obs: "We took a tour up into the Maid today. A generally stable snowpack in the area, new snow seemed to bond well with the underneath crust layer. We did observe small pinwheels/rollers on steep pitches on southeast aspects, mostly due to the rocks heating up during the day. We also observed sluff buildup on aprons below the shadier and steep northern aspects." Photo: Tommy S.

A slab avalanche was spotted from the highway. This slope is to the north of Lionhead Ridge a few miles. Photo: B. VandenBos

We skied into Lionhead Ridge on Wednesday, November 20th. The snowpack was shallow (6-18"), and mostly weak and faceted. This will make dangerous avalanche conditions when it snows more. Photo: GNFAC

"Lots of cracking up there this morning on fresh, mid elevation wind slabs"

Photo: B. Nobel

"While skinning up to the top of Powder Park lift at Bridger, we had roughly 15' cracks propagate on an E/SE aspect. A snowpit showed roughly 8" of wind slab above a few inches of facets, on top of last week's rain crust." November 11, 2019.

Photo: G. Lawrence

On November 8th, skiers found weak facets and surface hoar had formed during prior cold and dry weather. Keep an eye out for these weak layers if they get buried. Photo: B. VandenBos

On November 8th, skiers found weak facets and surface hoar had formed during prior cold and dry weather. Keep an eye out for these weak layers if they get buried. Photo: B. VandenBos

Skiers in the Taylor Fork observed faceting, or weakening of the snow, at the base snowpack in the Taylor Fork. Photo: B. VandenBos

Wind scoured down to the melt-freeze crust in the Taylor Fork. Photo: B. VandenBos

Wind was working hard, digging down to, picking up, and transporting dirt in the Taylor Fork. Photo: B. VandenBos

Wet loose avalanches at Bridger Bowl (observed on 11/5).

Photo: G. Antonioli

Wet loose avalanches at Bridger Bowl (observed on 11/5).

Photo: G. Antonioli

We found sensitive wind slabs near ridgelines on Mt. Blackmore and evidence of recent cross-loading. Photo: GNFAC

Small storm slabs triggered at Bridger on 10/26. From email: "slab formation appeared isolated to leeward sides of midslope terrain features and rollovers as well as at ridgetops". 

Photo: G. Antonioli

Large avalanche observed on 10/25 near Imp Peak in the Taylor Fork. Photo: B. VandenBos

Large avalanche observed on 10/25 near Imp Peak in the Taylor Fork. 

Photo: B. VandenBos

A local near Fairy Lake gets a taste of fresh October snow and wind. "You know it's somewhat windy when the goats start closing their eyes and their beards get blown sideways." Photo: B. VandenBos

Strong westerly wind scoured snow off high ridgelines and slopes in the northern Bridger Range on Friday (10/11). Photo: B. VandenBos

Dry loose snow avalanches were observed on 10/10 as the recent snow settled. From e-mail "...saw some small, solar-initiated, dry loose snow slides in steep, rocky terrain (heads up ice climbers). With a firm surface beneath the new snow, these little guys were picking up steam quickly." Photo: B. VandenBos

Avalanche debris on the saddle near Hyalite Peak. This is indicative of the type of heavily wind loaded terrain near ridgelines where avalanches are most likely this time of year. Photo: B. VandenBos

We put up the Lionhead weather station on Tuesday, October 8th. There was 4-6" of snow above 8,000'. Photo: GNFAC

Broken off cornice on the saddle between Blackmore and Elephant on 10/5. "Snow was anywhere from inches deep with grass and rocks to hip deep. It was mostly knee deep though. Down in the flats below the bowl there was easily 8-10" fresh and another 2" on my way down..." Photo: @benjacobsenphoto