How To: Snow Profiles & Tests

Doug Chabot of the Gallatin National Forest Avalanche Center demonstrates how to dig a snow profile with stability tests.

[@SamHaraldson]

A great recap on this, Doug. Thanks.

[@TitanStraps]

Great, educational video on digging pits! Nice work Doug!

[@romanmajor5850]

instaBlaster...

[@jgurtz]

Nice to see this professional demo

[@oceanside128]

love this very helpful reminders

[@bartgreen9497]

Good job Evan.

[@Assassinator05]

really nice stability choice if you want to measure your next life´s horoscope trough your layers of skin during a fresh powder run before you´re starting to identify columbo´s real character.

[@cualquiercosa5201]

Great video!! So informative.. thanks. What's the risk on skiing on that?.. I still wouldn't know if it's safe to ride on that or if maybe i should go home..

[@tomlives]

I'm just going to echo what half of the comments here state/ask: very good and thorough demonstration of how to build a pit etc., so thanks for that, but there are no explanations of what is good and bad in terms of the analysis.

[@MTavalanche]

Hi Thomas, Check out this newer video on ECTs for the answer to your question kzbin.info/www/bejne/fZybiGukobqAptk

[@SomeTechGuy666]

You need to tell people to fill in their snow pits after they are done !

[@liamelliott3779]

Your videos are very informative and I'm grateful that you've taken time to make them! Being an avalanche professional, what is your experience in observing amateur skiers of different levels? What level of caution do they use when assessing localized avalanche risk, and which tests are they likely to perform, if any?

[@MTavalanche]

Liam, The most popular tests are the Compression Test and Extended Column Test. These yield pretty good results. We see folks with lots of experience use tests and others do not. The same for beginners. It really depends on what type of information you want in regards to the level of risk you are willing to take.

[@liamelliott3779]

Interesting to hear that some experienced folks don't bother performing tests before going at it. I have absolutely zero avalanche experience as I don't live anywhere near avalanche prone terrain, but I will be moving somewhere where they are a real concern later this year. Can you recommend some good resources on avalanche science that would give me a strong theoretical base before I have the chance to take more practical courses in the fall? I heard The Avalanche Handbook is used frequently in professional training so I'll pick a copy up, but are there any other sources that would be beneficial to look at?

[@MTavalanche]

The Avalanche Handbook is great, but a little outdated with the explanation of fractures. Check out Snow Sense by Doug Fesler and Jill Fredston.

[@MrBlueboy6666]

Good video! I learned about standard pit procedure, where I struggle is how you'd analyze these results. How would you react to this situation? why? I'm sure I'll figure all this out when I take that avy 1 course though

[@MTavalanche]

Nate, a snowpit is just one part of the picture. When you get unstable results it can be a good sign to choose different/safer terrain. Stable results always have to be taken in consideration with other signs of instability. Recent avalanche activity or collapsing of the snowpack take precedent. Snowpits and stability tests can provide valuable info, but it takes years of experience before you can put a lot of confidence into your interpretations. Enjoy your level one, and read your local avalanche advisory to gain some more knowledge. Cheers!

[@philwaters9751]

Superb and consise... :-)

[@MattAppleford]

Great video, thanks for posting this Doug, great information and very easy to follow. Can you please tell me what the lens is that you are using? I've not seen that one before and would like to know more about it. Cheers Doug!

[@MTavalanche]

+Matt Appleford I'm using a Pentax monocular, but they don't make it anymore. The closest one available is the one that Snowmetrics sells: snowmetrics.com/shop/magniscope-30/

[@MattAppleford]

That's great intel Doug, I will check them out. I like idea of using a longer lens like that, to help preserve the snow sample when you are looking at it. I have a pretty powerful loup, but being so close to the crystal card (which is metal, I notice you use plastic, that might be another way to keep the measuring surface colder?), your face/heat tend to heat things up quickly and the grain doesn't last long in it's original state. So, I'm thinking a plastic crystal card, combined with that longer style lens you are using, will help make easier snow grain/crystal type evaluations that last longer? Thanks for the helpful reply!

[@elliotquinn5021]

Great demonstration, but is there another video of the analysis of the data/snow characteristics recorded and what they mean?

[@MTavalanche]

Elliot, For details on recording the snowpack layers and specifics on how to perform certain tests, check out the Snow, Weather, and Observational Guidelines from the American Avalanche Association. www.americanavalancheassociation.org/pub_swag.php

[@burrows10011]

Your videos are always great. Do you (or anyone in this thread) have a good one that shows HOW to use this information to decide whether to ski a certain face/slope. It seems like EVERY snow pit video shows week layers and faceting. Seems like someone should NEVER ski back country.

[@harz5935]

Maybe every snow pit video shows weak layers, because otherwise the video wouldnt show anything.

[@masoneley461]

Diligent and concise. I, like a fellow commenter, am curious if you deemed the slope safe to ski after your findings. So did you? Also, it looks more like a whiteboard, right? ;). Thanks for the videos

[@MTavalanche]

I kept the skins on and skied back out. I did not ski the steeper terrain below me.

[@richardbarton7]

enjoyed seeing if i got the decision right, good way of testing peoples proficiency watching like videos and seeing if the student makes the same choice ( ski or not to ski ) as the pro.

[@seanmenk219]

So WOULD YOU SKI IT? obviously the same layer continued to fail in each test but did that failure tell you it was a no-go? If so what then? Do you ski the track out? Pick a safer line (more in the trees, against one side rather than the middle, etc). Thanks

[@franceiroca]

Asking the same question...

[@Mr123pbd]

That's a pretty low angle slope I would say it's the prayer flags in beehive basin leads you to bear

[@bob15479]

that's literally what I ask myself on every one of these videos. can't find a single one where they give and actual diagnosis so to speak

[@hoffmanfiles]

Exactly

[@spencereng]

"I kept the skins on and skied back out. I did not ski the steeper terrain below me." - Taken from a question below where he answers it.

[@JoseAravenaAsesor]

Is the example done with the sun on your back?

[@franceiroca]

The question is : would you ski the terrain in this video?

[@skiaddict08]

No he didn't

[@smacnee3278]

No it propagated q1 at @15

[@BrianBraunsteinNow]

Rather, the question is what terrain would he be willing to ski given the results. He would likely ski the immediate terrain in the video since he and the camera person already entered it and thrashed around. Therefore, it's apparently safe terrain, meaning some combination of low angle, low consequence, small slope, etc. The results will then either confirm whether the plan he already made for a similar but more dangerous slope is safe enough, or the results may steer him to a backup plan. If his original plan was already very conservative then maybe he'd be able to stick to it. That said, with a plan conservative enough to keep going with those results, you probably don't need to waste time digging a pit.

[@JohnSerjeantson]

@@BrianBraunsteinNow it literally says on the snow profile "we skied the slope. Ski tracks on slope. Supportable crust." They decided a CT score of 15 with a supporting crust was fine.

[@BrianBraunsteinNow]

@@JohnSerjeantson I assumed they skied it, but looking at those notes now, I'm surprised to see it was 36 degrees, close to the center of the curve. Unless it was a small low consequence slope I would not call that a go for me. It clearly propagated well with Q1 without too much force and not so deep to be safe, but deep enough to send a heap of snow down. The profile has that crust drawn as rather thin. This guy is way more of an expert than me for sure, but my feeling is unless you're a hero like him and can evaluate very subtle points, this would be no go results for 36 degrees terrain with consequences.

[@tillybronte]

I am learning about avalanche risk so ask, is it ok to do this test just below large cornice?

[@MTavalanche]

Chris, you want to test a slope similar to the one you're interested in. If you're interested in a wind loaded slope, digging below a cornice can make sense. But safety is paramount, you'd only want to do that if you're confident that the cornice is not going to fail above you.

[@robertrepka1372]

Hey, I am also wondering. Should I ski a slope like this?

[@Chris11249]

I would not, and the instructor didn't either.

[@maxe2820]

no

[@kifer2594]

This is unintentional asmr

[@dannyisrael]

How did you isolate the back?

[@dannyisrael]

On the ECT

[@josephastier7421]

5:54 No go.

[@ThePerpetualStudent]

Forgive my ignorance but I am just getting into the whole backcountry boarding explosion and we are getting tons of snow in Cali right now. I would just like to be safe. After doing a column/compression test would it be wise of us to toss some large scale fireworks if the ultimate precautions were taken? I have heard of people doing this and just want to get your perspective on it.

[@BC-mf5gr]

No wonder California is always on fire...

[@Useryofcsdnx]

Seems complicated

[@trevorenglish6594]

So is it a go or a no