D2.5 slide Bridger Bowl sidecountry

[swimmy]

This was posted in the Montana thread but thought I'd share here as well.

Yesterday (Jan 15) a skier triggered a big slide in Argentina Bowl off Saddle Peak, just south of Bridger Bowl ski area. We've received about a foot of new snow in the last few days and yesterday folks started pushing it. There were tracks all over this thing. Most tracks are lookers right of these photos and can't be seen.

Conditions were considerable on wind loaded slopes and moderate every where else. SW Montana has been in a nasty avalanche cycle all season with persistent weak layers. Another slope on Saddle just slid 5 days ago also triggered by a skier. Fortunately no one has been hurt in any of these incidents.

From email sent into the Avalanche Center:

"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!!"

[Mountainman]

Where is it described as a D3?

[swimmy]

Yesterday when I first saw the report I thought I saw D3. Looking now it is reported as R3 D2.5. Maybe I just looked at it wrong.

Are half ratings official?

https://www.mtavalanche.com/node/21587

[total_immortal]

D2.5 not 3

https://www.mtavalanche.com/node/21587

[idahospud]

Yesterday when I first saw the report I thought I saw D3. Looking now it is reported as R3 D2.5. Maybe I just looked at it wrong.

Are half ratings official?

https://www.mtavalanche.com/node/21587

Half ratings are acceptable.

Not that we were at risk of heading over there on limited time, but this is a nice reinforcement of our brief chat looking at Saddle yesterday. "Yup, not a line I'd take this morning."

[stuckathuntermtn]

Is your snowpack as fucked over there in SW Montana as it is over here in Western Montana?

[Tindogger]

It's always a bit of a wake-up call to see those faces you know are so frequently skiied sliding the way they have been this year.

[Bunion 2020]

I guess. When I look at those "faces" I see big avalanche paths.

The trim lines and the lack of trees should be a pretty good clue.

[swimmy]

Not that we were at risk of heading over there on limited time, but this is a nice reinforcement of our brief chat looking at Saddle yesterday. "Yup, not a line I'd take this morning."

After you left I headed over to Slushmans for a few laps. As we rode the chair up we'd watch people ski down the Football Field. At one point, there were multiple people skiing the slope at the same time.

What goes on over there sometimes just leaves you scratching your head.

Is your snowpack as fucked over there in SW Montana as it is over here in Western Montana?

Yep. Poor structure pretty much everywhere.

[Bunion 2020]

Taylor mtn. Tetons ^^^

As we rode the chair up we'd watch people ski down the Football Field. At one point, there were multiple people skiing the slope at the same time.
What goes on over there sometimes just leaves you scratching your head.

Buddies of mine who used to work at the Canyons dealt with the same scenario. They solved the problem by putting up some blinds. When the lemmings were treking out the gates to Dutch Draw during periods of elevated hazard they would close the blinds so as not to have to watch.

[idahospud]

Buddies of mine who used to work at the Canyons dealt with the same scenario. They solved the problem by putting up some blinds. When the lemmings were treking out the gates to Dutch Draw during periods of elevated hazard they would close the blinds so as not to have to watch.

That's brilliant. I could learn a thing or two from these guys. That falls perfectly under "not my circus, not my monkeys."

[bodywhomper]

That photo at top thread shows several tracks the looker’s right Bowl. Does that bowl have the same persistent weaknesses? I’m assuming yes....

[Meadow Skipper]

That photo at top thread shows several tracks the looker’s right Bowl. Does that bowl have the same persistent weaknesses? I’m assuming yes....

One of the more eye-opening exercises I’ve done is to do stability tests in different spots of the same or similar locales. Lesson learned: just a relatively short distance between test pits can give remarkably different results, so don’t make assumptions.

That doesn’t answer your question directly, but it can help explain that picture.

[bodywhomper]

One of the more eye-opening exercises I’ve done is to do stability tests in different spots of the same or similar locales. Lesson learned: just a relatively short distance between test pits can give remarkably different results, so don’t make assumptions.

That doesn’t answer your question directly, but it can help explain that picture.

Thanks for the response. My question was more related to wondering if people had skied a slope that others with a first hand understanding of hazard would have considered suspect.

[Meadow Skipper]

Thanks for the response. My question was more related to wondering if people had skied a slope that others with a first hand understanding of hazard would have considered suspect.

Gotcha.

[1000-oaks]

One of the more eye-opening exercises I’ve done is to do stability tests in different spots of the same or similar locales. Lesson learned: just a relatively short distance between test pits can give remarkably different results, so don’t make assumptions.

The "ah-ha" moment for me was to stop looking at "slopes" or "aspects", and instead think in terms of the snowpack being a patchwork quilt, with each patch having it's own unique combination of ground cover, slope angle, solar exposure, wind history (adding or subtracting snow), snowfall history, skier compaction (or lack thereof), etc.

[swimmy]

That photo at top thread shows several tracks the looker’s right Bowl. Does that bowl have the same persistent weaknesses? I’m assuming yes....

Pretty much our entire forecast area (SW Montana) has been dealing with persistent weak layers all season. There have also been multiple large avalanches on different aspects in the Bridger Range within the past 10 days. Including this one to the north.



So it is safe to assume that all slopes, including those with tracks, have weak layers.

One of the more eye-opening exercises I’ve done is to do stability tests in different spots of the same or similar locales. Lesson learned: just a relatively short distance between test pits can give remarkably different results, so don’t make assumptions.

Spacial variability agrees with your post.

[bodywhomper]

Pretty much our entire forecast area (SW Montana) has been dealing with persistent weak layers all season. There have also been multiple large avalanches on different aspects in the Bridger Range within the past 10 days. Including this one to the north.



So it is safe to assume that all slopes, including those with tracks, have weak layers.



Spacial variability agrees with your post.

Thanks for the response. Damn! Clearly, those people that laid the tracks missed the trigger points. No bueno. I hope peeps make good decisions out there!