Recent Avalanche Activty 1/31

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maverick
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Recent Avalanche Activty 1/31

Post by maverick » Mon Feb 01, 2021 1:56 pm

Eastern Sierra Avalanche Center:
Make no mistake we are dealing with a dangerous snowpack at the moment. A heavy new load sitting on top of a weak base = avalanches that are difficult to predict but have the potential to be large and destructive. A wide range of avalanche activity has been reported in the last couple of days. Most notably a skier triggered persistent slab avalanche in the Punta Bardini area of the Sherwins on the afternoon of 1/30.

Image 1: An incident occurred this afternoon in the Punta Bardina area of the sherwins resulting in a Very large, Skier triggered, persistent slab avalanche. The avalanche had a 4-5ft deep crown, was 300-400 ft wide and ran for about 1500 ft. One skier was caught, carried and injured. Thankfully it was not worse. The red line represents the crown line. The Black x represents the spot where skier 1 triggered the avalanche and the circle represents where skier 1 was able to stop themselves by grabbing a tree.

Image 2: Widespread natural persistent slab and wind slab avalanche activity in Lee vining Canyon. The very large wind slabs on the high peaks likely occurred mid storm and have largely filled back in. The Persistent slab activity near and below tree line likely occurred near the end of the storm on the morning of 1-29 and ranged in size from large to very large.

Images 3 & 4: A very large avalanche occurred on the east side of McGee Mountain yesterday afternoon(1/29). Reports suggest this avalanche occurred naturally mid-day after a party ascended through the path. (Image 3) The avalanche slid through and covered much of there skin track. (image 4)

Thank you to the parties involved for coming forward and sharing the details of these incidents so that we can use them as a learning opportunity. We are grateful for your transparency and vulnerability.
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Re: Recent Avalanche Activty 1/31

Post by Wandering Daisy » Sun Feb 07, 2021 12:53 pm

There have been so many avalanche deaths this last week, in Colorado and Utah. So sad. I do not understand why anyone goes out when the avalanche warnings are readily available and the danger is at its highest risk category. Are people really ignorant of the deadly power avalanches? I have walked by summertime avalanche debris while backpacking - does anyone really think they could survive that?

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Re: Recent Avalanche Activty 1/31

Post by SSSdave » Sun Feb 07, 2021 3:07 pm

The issue isn't necessarily going out into the backcountry to ski but rather doing so in avalanche prone areas. Avalanches generally occur on 60%+ gradient slopes and fair numbers will incorrectly think if they just ease off to 40% and 50% gradients they should be safe. Instead they ought seek 20% to 30% grade slopes, however many have not learned how to ski powder in those areas.

Given 2+ decades of dominant bro culture ski movies with continuous segments of launching off steep ridgeline drops at warp speed and hucking hucking, it is no wonder many younger generation snow enthusiasts are so focused on skiing steep fresh powder slopes versus what had been traditional powder skiing of medium and lower gradient slopes. Part of that is because modern wide ski designs make that possible. Many less than advanced skiers that can hardly make S turns in powder will nevertheless launch off steep ridge line drops, accelerating at high speed and then deaccelerate in a slow run out arc. And then take that same style into the skin and boot pack slopes where avalanches are possible. There are plenty of 20% to 30% grade slopes accessible from plowed highway pullouts that are relatively ignored.

From Jackson Hole this week, a talented gal making great powder turns in spectacular fresh "blower" powder:

www.instagram.com/p/CK7PHECH4HQ/?utm_so ... atch_again

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Re: Recent Avalanche Activty 1/31

Post by SNOOOOW » Mon Feb 08, 2021 9:26 am

SSSdave wrote:
Sun Feb 07, 2021 3:07 pm
The issue isn't necessarily going out into the backcountry to ski but rather doing so in avalanche prone areas. Avalanches generally occur on 60%+ gradient slopes and fair numbers will incorrectly think if they just ease off to 40% and 50% gradients they should be safe. Instead they ought seek 20% to 30% grade slopes, however many have not learned how to ski powder in those areas.


Do you mean avalanches are less likely to occur at slope angles of 60 degrees and above? Anything above 60 degree slope angle and the snow generally sluffs off more frequently which makes larger avalanches less likely to happen. Most avalanches occur between a slope angle of 30 degrees - 45 degrees. I think the problem is people venturing into the winter backcountry without any avalanche basics or training. The avy courses around the Tahoe basin and Sierra eastside have had huge numbers requesting classes and they just cannot keep up with demand. I was up at Donner the other weekend, which I never travel to, and I could not believe the amount of people out there traveling in the backcountry, it was insane. I am sure a lot of those people have no safety gear on them or even checked the SAC forecast before venturing out. Be safe out there, I know we are all tired of being cooped up but enjoy yourselves safely :drinkers:
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Re: Recent Avalanche Activty 1/31

Post by c9h13no3 » Mon Feb 08, 2021 9:59 am

SNOOOOW wrote:
Mon Feb 08, 2021 9:26 am
Do you mean avalanches are less likely to occur at slope angles of 60 degrees and above?
Degrees are not the same as percent. A 45 degree slope is a 100% gradient.

I would address the ridiculousness of Dave's post, but no one has that kind of time.
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Re: Recent Avalanche Activty 1/31

Post by c9h13no3 » Mon Feb 08, 2021 10:04 am

Wandering Daisy wrote:
Sun Feb 07, 2021 12:53 pm
I do not understand why anyone goes out when the avalanche warnings are readily available and the danger is at its highest risk category.
The short answer is: it's fun. People do all sorts of risky **** for fun, like for an example you may understand: rock climbing. If you can't understand it, you're not thinking very hard.
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Re: Recent Avalanche Activty 1/31

Post by SNOOOOW » Mon Feb 08, 2021 10:25 am

c9h13no3 wrote:
Mon Feb 08, 2021 9:59 am
SNOOOOW wrote:
Mon Feb 08, 2021 9:26 am
Do you mean avalanches are less likely to occur at slope angles of 60 degrees and above?
Degrees are not the same as percent. A 45 degree slope is a 100% gradient.

I would address the ridiculousness of Dave's post, but no one has that kind of time.
Ahh I gotcha, I felt we were referring to different things. Thanks for the correction.
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Re: Recent Avalanche Activty 1/31

Post by SNOOOOW » Mon Feb 08, 2021 10:29 am

c9h13no3, I forgot to mention a few months back I actually clicked the link to your blog. I couldn't resist the "Please do not click" temptation. There are some very fun adventures I enjoyed reading about. Thanks for sharing
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Re: Recent Avalanche Activty 1/31

Post by Wandering Daisy » Mon Feb 08, 2021 5:43 pm

My question as why someone would do this should have been less general. The people killed recently were skiing specific slopes as well as general areas with same-day highest risk avalanche warnings. The guys killed in Colorado a few weeks ago were skiing a chute well known for avalanches and previous deaths and in spite of severe avalanche warnings. It had just snowed several feet with wind up to 100 mph. So you say "for fun". I agree, fun when conditions are right; stupid when not. Being "experienced" makes no difference. Avalanches do not care if you are experienced, have "avalanche safety gear" or not.

In my climbing days (also did up to 3-week long winter mountaineering) I was well aware of the risks, but never specifically got jollies out of risk itself; it was the climbing that was fun. We were well trained in risk management and had a high respect for the forces of nature. Yes, I am an old timer- we had no avalanche beacons, avi-vests, GPS, or other means of emergency communication. Because of that I think we were more conservative than today's backcountry skiers. I recall that I read recently that all the avalanche safety gear available nowadays has not reduced the death statistics; in fact the opposite.

All the recent deaths are sad, and how horrible for the loved ones and what a waste of lives in their prime.

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Re: Recent Avalanche Activty 1/31

Post by c9h13no3 » Tue Feb 09, 2021 9:55 am

Wandering Daisy wrote:
Mon Feb 08, 2021 5:43 pm
My question as why someone would do this should have been less general. The people killed recently were skiing specific slopes as well as general areas with same-day highest risk avalanche warnings. The guys killed in Colorado a few weeks ago were skiing a chute well known for avalanches and previous deaths and in spite of severe avalanche warnings. It had just snowed several feet with wind up to 100 mph. So you say "for fun". I agree, fun when conditions are right; stupid when not.
People study this sort of thing, they've even got a fancy acronym (FACETS). The human brain is wired to take risks to gain rewards. We gamble money we can't afford to lose, take drugs that destroy our lives to get high, ski known avalanche paths with high danger, and drive recklessly on the highway. It's easy to judge from the outside as stupid (because it is a stupid decision), but our brains are all wired to make these dumb choices from time to time, and some people are more risk averse than others.

The number of people backcountry skiing has exploded, and yet avalanche deaths have not risen at the same exponential rate. Knowledge of the snow has increased dramatically with the internet, people probably do ski with a narrower margin of safety than they did back in the 80's. But they have more certainty about the state of the snowpack, so the smaller margin usually suffices. Yes, there are more people doing dumb things out there, but that's mostly because there are just more people.
"Adventure is just bad planning." - Roald Amundsen
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