Avalanche

[raisingarizona]

I am wondering....

When it's early, and there is very little snow, and it is windy, does that lead to the more variability?

Is it possible that he line he skied, that broke off so easily, could be right next to something that was stable?

You could see from the stills of the crown, that it wasn't a wide layer that was evenly thick, some part of it was shaped more like a crescent.

View attachment 21979

Will that ^^ bottom layer have a hard time bonding to new snow?

The other skier thing is eerie.

It’s possible that the other skier hit a more stable section for sure. It looks less loaded to the viewers left in that photo. It’s also possible to never really know where and when or what will be the trigger. I think the skier that slid though nuked it harder into the sweet spot. The skiers that go after the first guy often do hit it harder as their confidence is often better than the first person.

As far as the layers in the photo?

Snow is a lot like people in that it needs time to deal with and accept change. If you hit it too hard or rapidly changing the world it’s been getting used to and comfortable with it will often react negatively. That’s why a serious wind event creates a lot of spacial variability and instability. Just like people it’s best to ease them into a big change, give them space and time to come to circumstances with that change. Change is stress and stress leads to fear. Don’t go poking a stressed out dragon now.

I have no idea what the bed surface layer there is like but I’ve been totally convinced that a snow pack is f-d by some crazy rain layer or surface hoar or whatever and then been completely blown away how the two layers quickly get comfy with one another. Deep rot though or what most people refer to today as a PWL is a different monster all together. That’s when things get really scary. Wind loading, slab development is something I can generally see, it’s right there in front of you and on the surface but a pwl is different and often just eerie af.

 

[Benny Profane]

Craziest avalanches are those that break down to the rock. After watching that news report, chances are that was a nice looking wind slab resting on that ice.

 

[raisingarizona]

Craziest avalanches are those that break down to the rock. After watching that news report, chances are that was a nice looking wind slab resting on that ice.

This one broke from under those rocks. Crowns often connect rock out croppings and tree islands since that’s where TG (temperature gradient) snow usually develops the most.
This bed surface didn’t look like TG snow and more of an older hard layer. Maybe another slab and/or rain crust from the rain event mentioned in the report. I really have no idea from looking at the short video clips but my guess is that that pocket just caught a bunch of snow like a catchers mitt during the last wind event and sat there waiting for a trigger.

 

[raisingarizona]

When the whole pack goes straight to the ground we’d call it a climax avalanche. I guess I don’t know if that’s an actual snow science term or it was skier slang.

Climax slides can be wet avalanches when late in the spring there’s running water below the base of the pack from continued warming or from rotted early season snowfall at the very base (a PWL of TG snow) that’s reached its breaking point with load. Those big wet avalanches are why we get an early start for spring tours, often referred to as an “alpine start”. I’ve always been very punctual with the temperatures and timing. These aren’t things to be taken lightly.

For the record, I don’t think the industry has recognized TG (temperature gradient) as the proper terminology for 10 or 20 years now, I have no idea why. I always liked it and it helped me understand snow rot deep within a pack.

 

[tirolski]

For the record, I don’t think the industry has recognized TG (temperature gradient) as the proper terminology for 10 or 20 years now, I have no idea why. I always liked it and it helped me understand snow rot deep within a pack.

The Canuck's Avi Center defines it.

Glossary

Glossary

avalanche.ca

The first dude who took a pick of a snow flake .

Snowflake Man Bio — Snowflake Bentley

snowflakebentley.com

Ain’t 2 the same.

 

[Mike]

Hello everyone, great discussion here. AG is one of the few lines at Mt. Washington that I have actually skied. We did a similar tour, up the cog side via the jewel trail, took a run on AG, booted up and came down Ammo...we did it in the spring in t-shirts, corn snow and bomber snow pack....It's a spicy line. Real steep for a long ways with a huge boulder part-way down that you have to miss. Even with good snow, if you fall, you will almost certainly be severely injured as you free-fall ping-pong starfish down and bounce off the rock walls. Even considering skiing it after reading the MWAC avi report for that day is nuts. I've had a bit of fun on some of the FB pages about this, I called the skier 'stupid' ( I know) and pushed back against some folks who believe that the skiers did nothing wrong and accidents happen. Well, if my tour ended with a ride in a Blackhawk, you can be sure I would be thinking I made some major mistakes that day. I hope the skier keeps his leg, and skis again.

 

[tirolski]

Hello everyone, great discussion here. AG is one of the few lines at Mt. Washington that I have actually skied. We did a similar tour, up the cog side via the jewel trail, took a run on AG, booted up and came down Ammo...we did it in the spring in t-shirts, corn snow and bomber snow pack....It's a spicy line. Real steep for a long ways with a huge boulder part-way down that you have to miss. Even with good snow, if you fall, you will almost certainly be severely injured as you free-fall ping-pong starfish down and bounce off the rock walls. Even considering skiing it after reading the MWAC avi report for that day is nuts. I've had a bit of fun on some of the FB pages about this, I called the skier 'stupid' ( I know) and pushed back against some folks who believe that the skiers did nothing wrong and accidents happen. Well, if my tour ended with a ride in a Blackhawk, you can be sure I would be thinking I made some major mistakes that day. I hope the skier keeps his leg, and skis again.

Somebody interviewed him & wrote this recently.

New Hampshire man shares scary moment he is caught in an avalanche while skiing on Mount Washington

"I just I felt everything just release beneath me."

www.wmur.com

 

[Mike]

Thanks for sharing this. Yikes, 4 surgeries.

 

[Ripitz]

Big avalanche off KT-22.

1 killed, 3 injured in avalanche at Palisades Tahoe ski resort, California officials say

An avalanche at Palisades Tahoe ski resort on Wednesday morning killed one skier and injured three others in northern California.

www.usatoday.com

 

[Brownski]

That is wild. Hope there’s nobody underneath it.