Regional Conditions for Bridgers

We went to look at the snowpack on Saddle Peak in the backcountry south of Bridger Bowl (12/5/19). Heavily wind loaded slopes have hard slabs over weak facets. Unfortunately this poor snowpack structure will be with us for a while in the backcountry. It will not get compacted by skier traffic or show obvious signs of instability. SKi patrol triggered this slide just inside their boundary. This is the first time they have done control this season, so it is a glimpse of what we might find in the uncontrolled backcountry snowpack. Photo: GNFAC

This large avalanche was triggered intentionally by the Bridger Bowl Ski Patrol at the ridgeline above little Slushman's Ravine. They were cutting a cornice and it broke 7 feet back from the edge, 4 feet deep and 150 feet wide. It was a hard slab avalanche and ran 1150 feet. It was east facing and broke on a crust formed in the early season. It's code is AC-HS-R2-D3-4'-O-TL-1150' Photo: BBSP

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

We skied in the northern Bridgers (12/2/19), and an unstable test result (ECTP14) prompted us to adjust our travel plans. In the mountains around Bozeman and Big Sky the snowpack is generally stable, and will get more stable without snow the next few days, but it is just as important as ever to carefully assess stability of each slope, each day you plan to ride in avalanche terrain. East aspect. 8,100' elev. Photo: GNFAC 

This avalanche of wind-drifted snow was triggered with a ski cut on a southeast aspect at 9,800'. Photo: T. Chingas

This slide was triggered up Hyalite from 100' away. It was a wind loaded slope at 9,000', northeast aspect. Photo: T. Chingas

From an observation:

When approaching the base of Mt. Blackmore this morning at roughly 8:45 am we observed strong swirling winds at higher elevations (summit of Blackmore and the Elephant/Blackmore Saddle). The winds we observed were primarily loading snow onto E and SE facing aspects. Furthermore, we witnessed four naturally triggered avalanches over a twenty minute span. All slides appeared to be D1/D2 on E and SE aspects and, seemingly, restricted to the newly loaded snow. Photo: SAM

This natural avalanche released on Saddle Peak. wind loading from west winds created sensitive wind slabs this morning. Photo: S. Jonas

Skiers found reactive wind slabs near the ridge line that easily avalanched. Photo: S. Jonas

From obs.: "New snow from 24 hours ago blew around the ridge tops from 11pm last night until 7am this morning ~30mph. This soft 4 finger slab was about 6”-7” deep and broke on a convex roll.... We were assessing the terrain carefully and expected this result." Photo: R. Christian-Frederick

We triggered this dry loose avalanche on a west facing slope in Beehive Basin on 11/30. 3-5" of recent snow easily slid on top of a crust. Photo: GNFAC

Dry loose snow avalanches were easy to trigger on Saturday 11/30 in Beehive Basin. Photo: GNFAC

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

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

Large surface hoar in Hyalite on 11/23. Photo: C. Kussmaul

Shooting cracks in Hyalite at ~9500 ft on a N aspect on 11/23. 

From obs "We got some large shooting cracks while skinning and ended up turning around." Photo: C. Kussmaul

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.

Toured up to the ridge at Bridger today and traversed into Bridger Gully. At around 8,000' in the trees above the most prominent snowfield, my partner and I observed very small dry sluffs confined to the new snow.  Bellow Bridger Gully, my partner was able to release a slide while traversing through rocks above his intended line. This was on an east-southeast aspect at 7,500'. Photo: Cole Oshiro-Leavitt

On Thursday 11/21 skiers at Bridger noted: "...some activity (D1-D2) isolated to the new snow around rock features and ridgetops that were wind-affected..." Photo: G. Antonioli

On Thursday 11/21 skiers at Bridger noted: "...some activity (D1-D2) isolated to the new snow around rock features and ridgetops that were wind-affected..." Photo: G. Antonioli

From obs.: "I went skiing at Bridger today,... There was 4-5” of new snow, which was sitting on a firm surface. The wind had done some work, and I was able to break off a few shallow (6”) wind slabs in the first 100 feet or so off the ridge." Photo: A. Schauer

A skier on Saturday (11/16) took the time to dig a quick pit about 200' below east ridge of Mt Blackmore. He found about 2.5 feet of snow with a few crust layers. Photo: K. Stewart

This wet loose avalanche was on a west-southwest aspect in Beehive Basin. It broke to the ground (only 30 cm deep) but shows how a few hours of sun with above freezing temperatures can create wet slides, even in November! Photo: McKinley Talty

These feathery surface hoar crystals were buried under 5" of snow last night up Hyalite. These weak grains may become a problem with additional load. Phoro: B. VandenBos

"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

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

My partner and I skinned up the Middle Fork of Brackett to Ross Peak hoping to ski a few different things up there. Again, pulled the plug due to stability concerns. The snowpack was significantly thinner and weaker than what I've seen up at Bridger and older snow was moderately faceted. Encountered a few thin, natural hard slab avalanches, failing on top of a facet/ melt-layer. Photo: B. VandenBos

E aspect, 9,100'. Triggered from a stomping a small cornice, which landed on a steep slope below and popped a small wind slab. Photo: T. Chingas

A skier reported on 11/1, "Activity I observed was restricted to the new snow. A fair bit of loose snow....  Skiers on the E bowl of Blackmore triggered some D1 dry sluffage, running on a crust beneath the new snow." Photo: B. VandenBos

A skier reported on 11/1, "Activity I observed was restricted to the new snow. A fair bit of loose snow....  Skiers on the E bowl of Blackmore triggered some D1 dry sluffage, running on a crust beneath the new snow." Photo: B. VandenBos

A skier reported on 11/1, "I watched a small (D1) wind slab build and fail as the wind picked up near the Blackmore/Elephant saddle (happened just before 2pm). Slab couldn't have been much thicker than 15cm, broke 30-40m wide. These slabs were building rapidly,..." Photo: B. VandenBos

Avalanche crown north of Bridger Bowl from avalanches that ran on or before 10/30. Photo: G. Antonioli

Avalanche crown north of Bridger Bowl from avalanches that ran on or before (10/29). Photo: G. Antonioli