Might as well have a thread here in addition to the thread on the main forum https://www.tetongravity.com/forums/...67#post7025967
CB News: https://crestedbuttenews.com/2024/02...anche-sunday/?
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Might as well have a thread here in addition to the thread on the main forum https://www.tetongravity.com/forums/...67#post7025967
CB News: https://crestedbuttenews.com/2024/02...anche-sunday/?
This one has been harder than most to read about, understanding how many of you all knew him well...the proximity of this tragedy is too close for comfort even though I never had the pleasure of meeting him.
They have updated the accident summary this morning with newer pics. Full report out later in the week
https://classic.avalanche.state.co.u...=863&accfm=rep
The CAIC final report has been released:
https://classic.avalanche.state.co.u...=863&accfm=inv
FUCK! That is a rough read.Quote:
Originally Posted by andy m
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signs, signs, everywhere there's signs
Rip in Peace Eric Freson, and condolences to friends and family.Quote:
Originally Posted by teleee
“The avalanche broke approximately 30 feet above Skier 3 and quickly swept him off his feet. The group below watched as Skier 3 deployed his airbag and was swept over the cliff band and onto the broad, open slope below. The initial avalanche triggered a second, larger avalanche on the open slope. This second avalanche added substantial volume to the flowing debris. He went out of view of the group.
The avalanche ran into trees below the open slope, taking Skier 3 for a violent ride. The impact ripped the airbag from his body. Skier 3 came to rest, fully buried about 500 vertical feet below where he triggered the initial avalanche.”
That is a rough read, and troubling on many levels.
Truly rough
In the report there is the mention that while skinning one in the group found the snowpack shallower than expected, can someone explain why that's a red flag?
Because it makes it much easier to trigger a PWL.Quote:
Originally Posted by kw_cap
...and because they were depending on a deeper snowpack in the zone to mitigate the PWL danger.
Got it, appreciate the explanation!Quote:
Originally Posted by cravenmorhead
Quote:
Originally Posted by cravenmorhead
I really have to question that line of thinking as extremely wishful.
Quote:
Avalanches are one of the most powerful natural occurrences — capable of wiping entire towns off the map — and typically associated with large amounts of snow. This year, the lack of snow is record-breaking, but avalanche risk remains stubbornly high.
The Gallatin National Forest Avalanche Center reported on Feb. 21 that large avalanches and other signs of snowpack instability are continuing with “alarming regularity.” Avalanche experts say this season is unprecedented in persistent avalanche danger, despite a low snowpack.
Avalanche danger is ranked “considerable” across all areas in the GNFAC’s coverage, and has remained in that range or “high” since the first week of February, according to the organization’s weather and avalanche log.
In fact, very few reports since December have labeled any area as “low” in danger.
“Stepping into backcountry avalanche terrain (slopes steeper than 30 degrees) anywhere in the advisory area is like stepping onto the casino floor with the odds stacked against you. You might win a hand or two, but you’ll likely lose in the long run,” forecaster Dave Zinn wrote in Wednesday’s report.
Normally, GNFAC director and forecaster Doug Chabot said, instability directly follows after snowfall before stabilizing after a few days. This season, however, the GNFAC is having to hold avalanche danger higher than they have in years because the snowpack is just not stabilizing.
“A small storm has been enough to spike the avalanche danger to where we are seeing lots and lots of avalanches with a minimal amount of snowfall, that’s unprecedented,” Chabot said.
The problem with this year’s snowpack is that the early season snowstorms stayed on the ground without being buried and turned into sugary, faceted layers which never strengthened, Chabot said.
When layers remain weak but have snow fall on top of them, the risk of dry slab avalanches — the type of avalanche experts are most concerned with — are more likely.
Karl Birkeland, an avalanche scientist and former director of the National Avalanche Center, said while the average person might think less snow means less avalanches, to a forecaster or snow scientist, it’s a red flag.
Dry slab avalanches are caused by continued snowfall accumulating on top of weak layers prone to collapse. Extreme cold, like the snap in mid-January can also contribute to these persistent weak layers, named as such because Birkeland said they stick around longer than anticipated, extending avalanche danger long after new snowfall.
People are still triggering avalanches days and even weeks out from new snowfall, Birkeland said.
He said this creates dangerous situations because skiers and riders tend to believe that they can wait a few days after snow, then go ski avalanche terrain.
“This is the kind of season where you really have to recalibrate and understand that this season is different than our average season,” Birkeland said. “You need extra margin of safety in order to make it through a season like this.”
Birkeland said this season is one of, if not the worst, snowpack he has seen in the 35 years he’s lived in Montana.
“If you’re not paying attention to the avalanche forecast, you might think it’s like any other year,” Chabot said.
In the past 10 days, dozens of natural avalanches and several skier avalanches have been triggered. On resulted in a partial burial of a skier slightly northwest of Yellowstone National Park.
In the GNFAC’s Feb. 20 report, Chabot wrote, “the mountains have been talking to us... The translation is easy; she’s telling us the snowpack is dangerous.”
He reported that fellow forecaster Dave Zinn encountered a large collapse near Cooke City — after safely ascending the slope and conducting a safety test on the snowpack. The report said if the slope had been even slightly steeper it might have slid.
Chabot emphasized that despite their name, stability tested are actually “instability tests” to be used to detect signs of avalanche potential when there are not already so many naturally occurring ones.
“Right now, we don’t need them. We’re seeing whumpfs and cracks and cracking and avalanches all the time,” he said. “That trumps a stability test.”
Chabot added that the coming weekend and week’s warmer temperatures might see more skier and rider traffic, increasing the potential for human-triggered slides on the already precarious snowpack.
People need to be careful, he said.
While Chabot said apart from rain or melting, nothing could totally rectify the situation, two opposite events could alleviate it — either a significant snowstorm or a complete dearth of snowfall.
“We’ve been talking about that happening ever since Dec. 1,” Chabot said. “We’ve been saying ‘well once it snows and we get that big snowstorm, it will really help.’ And here we are, at the end of February and we’re still kind of waiting for that big snowstorm.”
As for the no snow option, Chabot said while that would help stabilize the snowpack, it would also negate the whole reason why people go out into the backcountry — to have fun skiing powder.
It is unclear if this year’s sustained avalanche risk without minimal snow is just an anomaly fed by El Niño weather patterns, but Birkeland said in general a changing climate will make predicting avalanche danger more difficult going forward.
Because avalanches are driven by the weather patterns of any given season rather than larger climatic patterns, the scientific certainty on warming winters is less certain when it comes to predicting future avalanches seasons, he said.
For instance, Birkeland said if average temperatures increase and come with more rain, and less snow, there may be fewer avalanches. But a season with more temperature extremes and big storms on top of a thinner snowpack might see worse conditions.
“I think the biggest thing that we can say about avalanches in the future is that things are going to be different. Typically, we try to predict what’s going to happen in the future based on what we’ve observed in the past and the thing that’s going to be challenging for us with avalanches is that we are probably going to see things in the future that we haven’t seen before,” Birkeland said. “So, relying just on our past experience is going to be more challenging.”
Heuristic thinking and biases
^^^ Dig dig ding!
So many red flags.
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I agree. I think it's notably from a decision-making standpoint though, since the field observations weren't matching up with the conditions the team expected.Quote:
Originally Posted by Bunion 2020
Really shitty to read this as well as the thread on the main page. Sounded like a well liked person who will be greatly missed.
I am shocked that we have not lost anyone around here this year. Snow pack is as rotten as the SJs and people are numb to the dangers and getting after it.
We basically always have that layer in Colorado. What happens is eventually it gets buried deep enough that the midpack bridges the layer and you can ski avalanche terrain again if you have history with the region and know what it takes to bridge and have been keeping an eye on pack depth. A storm can reactivate it though by being too much load for the midpack to bridge.Quote:
Originally Posted by Bunion 2020
It sounds like they were counting on the midpack bridge. But perhaps what they didn't take into account was the surface hoar PWL (which they should have considered given the avy report), which we don't commonly see and is much easier to activate since it was right in the middle of the midpack and wasn't being bridged. It's not clear to me if it stepped down to the depth hoar or only slid on the surface hoar, but I think the latter.
Due to the surface hoar, and how unpredictable it can be in terms of location, I've been playing it pretty safe after it formed. Though before it formed, our depth hoar was so bad this year there really wasn't a good window where the midpack was bridging the depth hoar, so I've had to treat this year much more conservatively than I do most years. Local knowledge might allow you to step out, since if you were out a lot you'd know where the surface hoar formed and where it didn't, but with 2 young kids at home, I'm pretty out of touch. Anyway, that sums up how I'm looking at this year compares to others, and why I think they made the decisions they did, despite the typical depth hoar PWL that we always get.
Note: some people don't like the midpack bridge 'gamble', but in my experience, it's been pretty predictable, as we've experimented a lot with it over the years in our go-to zone, picking low consequence slopes or test slopes to learn more about what it takes to bridge and to learn what the factors are when it doesn't and even how it reactivates (2013 LL pass slide that killed several comes to mind). I don't think this works well universally across Colorado, but in areas with unusually high snowfall, like the Keblar Pass region, it can be done (in my experience).
Or so far you have been lucky. Different strokes and all that.
Thx
None of that really matters if they were triggering avalanches remotely and directly immediately before the fatal slide, no?Quote:
Originally Posted by Lindahl
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If you are going to roll the dice with a propagating PWL in the mid pack (surface hoar) that could potentially step down to a depth hoar PWL then your terrain choice needs to be carefully considered. Not all avalanches are killers, but some are and an airbag, Avalung or companion rescue will be of no use.
^^^The objective hazard on that terrain would give me pause with a consolidated spring snow pack
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100% agree with you. The write up and especially the pictures of terrain and snowpack made me shake my head.Quote:
Originally Posted by MagnificentUnicorn
From what I understand, the remote trigger slides were a southern aspect? We see activity all the time this time of year on solar aspects in our local terrain that have no relation to the stability of northern aspects in trees. Maybe they thought the same?Quote:
Originally Posted by MagnificentUnicorn
As for the direct, it was a small soft slab (it stepped down but they couldn't see that). Probably a pocket release with no real propagation potential that doesn't have unpredictable PWL characteristics. Not saying I'd make the same terrain choice (surface hoar only a few feet buried is not something I'd gamble with), but I can see how they continued if they weren't thinking about or aware of the SH problem.
Maybe chill a bit on the assumptions. It was a tragic accident. Mistakes were made. People are grieving.
Be humble. Learn. Thanks
If you want to call out someone specifically for an out of line comment, go for it, but don't guilt trip us all and shut down an informative thread where most people actually are being humble and learning.Quote:
Originally Posted by Foggy_Goggles
I disagree that my thoughts were inappropriate or aimed at anything other than learning (to the extent Foggy was responding to me). But I've deleted my comment.
Again, my condolences to all involved.
Incident debreifs often step into the hypothetical. Thats OK. Opining on what those involved where thinking is not. Its just my opinion.
I've been in this game a minute. The enemy is us. In retrospect, it is frequently easy to identify the mistakes. If you think you or your group would never make those mistakes, excellent. But you are probably wrong. Consistently conservative decision making from a position of hyper awareness is the game for the experience. Just because it's obvious don't mean it is simple. If you extrapolate it over your entire backcountry skiing career, it becomes incredibly difficult.
I'm not guilt tripping anyone. If you don't think it applies you your comment, that's your prerogative.
Watch this is you haven't
https://www.youtube.com/watch?v=EXjucDIpWKQ
I don’t think anyone is opining on what they were thinking. Personally I’d like to know what they were thinking. That’s incredibly consequential terrain in the most stable of conditions.
Personally I would never put myself on that hanging snowfield above cliffs with trees below but that’s just me. I know people have different risk tolerance but there’s really no room for any error or uncertainty on that slope. It’s akin to Russian roulette in my opinion.
I think that objective dialogue about an incident like this is healthy and educational
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Eric was a member of this community. He friends hang out here. If you honestly mean that, go in the ski forum, PM the CB backcountry skiers, and ask them for the contact information for skiers 1,2 and 4.Quote:
I don’t think anyone is opining on what they were thinking. Personally I’d like to know what they were thinking.
This is a bit of what I'm getting at. I'm sharing a bit of my emotions. There are plenty of topics to be discussed that can be of value and may help keep people, us included in the future.
How to manage a PWL
What is a Red Flag
Spacial Variability of Surface Hoar
Depth of Snowpack and how if affects stability
Is the a difference between Islands of Safety and Trigger Points
What a common heuristic traps and how to manage them
The Slide Zone is open 24/7 365. Start a thread, drop the knowledge. I'm just asking that you keep, what you would do or conjecture about why this happened to yourself.
Again, it doesn't make me right. Its just how I feel. I didn't know Eric but he is friends of friends. Not a day has gone by since his passing that I don't think about the accident. It just seems like unnecessary piling on to pass judgement and highlight the mistakes you feel they made.
This is the Slide Zone
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FWIW, I started this thread, even as a friend of Eric's, knowing that
a) there was already a really good thread in S/S forum to celebrate Eric
and b) there might be some uncomfortable discussion here in the Slide zone. Piling it on is of course not helpful. Thoughtful discussion is. I've actually wanted to respond to the deeper snowpacks thing above but haven't had the time yet.
Fair enough. I don't need to be right.
I'll try and dig up some information from people way more knowledgeable than me on bridging PWLs, managing instabilities that exhibit wide spacial variability, snowpack depth and how it relates to both depth hoar development and skier triggers and so on.
It's really above my pay grade and I'm not infront of a computer so if any of ya'll wanna get started, let'r rip!
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No, totally appreciate it and agree that hindsight is 20/20 and some comments weren't all that helpful and very much on the edge.Quote:
Originally Posted by Foggy_Goggles
I'd guess he was gonna jump the cliffs and he probably has done it before and has a nice line through them, I don't see any other reason to be above them, anyone who skis that area agree or disagree with this? Otherwise there are clean lines nearby that avoids that exposure the group would have skied right?Quote:
Originally Posted by MagnificentUnicorn
I would be interested in learning about bridging in PWL but on the other hand, I keep things simple. I'm more of a red light yellow light green light guy. IMO after a certain amount of experience the more you know about snow pack doesn't lead to safer decisions it often leads to more dangerous decisions (just an opinion and there are obvious big exceptions to this and my ignorance is showing here). Do I really need to become so confident I can outthink a PWL? This is me talking I'm not saying or implying that group thought this - I'm talking about ME ME ME. Also, frankly, I don't think I'm smart enough to be an expert at snow science.
I would be curious how GB and other locals deal with never ending snow instabilities year after year and still ski fun stuff.
This is the slide zone where learning can and should occur.Quote:
Originally Posted by Foggy_Goggles
I’m sorry for your loss, but this is the place for a respectful discussion on avalanche activity.
I'm still slacking. I'll try and keep in positive and see if we can stay safe together. It is as much, if not more, about doing than learning. So here is something I can speak to.
The CAIC has been talking about shallow snowpack generally and shallower spot in given lines and slopes as representing increased risk. I think about this in two ways.
1. the less snow between you and the PWL, the higher the probability that you will be the trigger.
2. rocks, shrubs, trees tend to manifest faceting in the snowpack
If you pay attention is the photos of observed avalanches, you frequently see the propagation "connecting the dots" between these features.
Yes, rocks, krummhoz, trees are not anchors they’re weak spots.
Shallow snowpack is always weaker in general terms.
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All relevant thoughts and observations.Quote:
I would be interested in learning about bridging in PWL but on the other hand, I keep things simple. I'm more of a red light yellow light green light guy. IMO after a certain amount of experience the more you know about snow pack doesn't lead to safer decisions it often leads to more dangerous decisions (just an opinion and there are obvious big exceptions to this and my ignorance is showing here). Do I really need to become so confident I can outthink a PWL? This is me talking I'm not saying or implying that group thought this - I'm talking about ME ME ME. Also, frankly, I don't think I'm smart enough to be an expert at snow science.
Bridging is a Colorado thing. As Dr. K. Birkeland once opined, "Bridging is another term for a slab".
https://www.researchgate.net/figure/...fig7_259509982
Yes, deep enough snow "can" bridge over weakness. Relying on that in times of multiple PWLs is really hanging it out there.
When I was working as as a SS Director I was said to be an expert at judging hazard and mitigating that hazard. Now that I have retired I can look back and see clearly that I was estimating hazard and dealing with that hazard in the way I had been trained. Through the use of explosives for slope testing and following a set of protocols. The biggest danger was me and human nature creating reasons to deviate from those protocols.
Same same.Quote:
I would be curious how GB and other locals deal with never ending snow instabilities year after year and still ski fun stuff.