When you think about evaluating the snowpack, digging a pit is a direct way to observe what the snow is doing in a given area. A snow pit is a crucial tool in assessing what we think is going on and verifying it or gathering more information to answer a specific question about the snowpack. If you’ve taken your Avalanche Level 1 or higher, you’ve stood inside the cold depths of one of these and dissected it. Unfortunately, like many things, without practice, we get fuzzy on what exactly we need to look for each time we dig.
Before you even begin to dig, ask yourself what you expect to find or see based on the weather patterns so far and the area you’ve selected. Is there a problem layer you think might be reactive? Remember that pretty surface hoar from a few weeks ago, do you know where it’s sitting and on what aspect? What specific questions are you trying to answer by delving into the snowpack? It’s helpful to approach your pit like an experiment. You have an idea of what you might find and when you dig you will either prove or disprove it, giving you more information to assess your ski terrain and potential hazards moving forward.

"Remember that pretty surface hoar from a few weeks ago, do you know where its sitting and on what aspect?"

With that in mind, here are a few of the top things to look for when analyzing your pits.

1 
​Spot the Obvious Layers:

When you start digging, note the most obvious things you’re seeing in relation to the snow. Problem layers can often be seen or felt as you start to dig out your pit. An ice layer is going to feel hard as you try to dig through it, just as noticing a clean sheer on a buried surface hoar layer can grab your attention as it continues to break at the same spot. Note what jumps out at you immediately. Is it what you expected or is it something you weren’t anticipating? Every step in digging your pit can give you information on how the snowpack is currently reacting. Observe any possible problem layers and mark them for further investigation on both your observation wall and in your backcountry journal.

​Spot the obvious layers

2

Identify the Differences in Hardness:

​This is a step that can easily be forgotten but is important. On your observation wall, identify the difference in hardness of your layers in the snowpack as measured by Fist, 4-Fingers, 1-Finger, Pencil, Knife, Ice. Thinking of the snow as a layer cake, you’ll be looking for noticeable differences; like an ice layer over facets, or a harder, denser layer sitting on top of a layer that could act as a sliding surface. This combination indicates the potential recipe for a slab and a surface for it to fail on.
Other things to look for are differences in snow density, especially between two recent storms. For example, if a denser, heavier layer is sitting on top of a lighter layer (upside down snow) you could have a slab and a failure at the density interface. Or if you find a harder wind slab sitting on top of a sun crust, ice layer or change in snow hardness, you’ll want to examine that closer. Identifying the different hardness layers can immediately bring your attention to a layer that’s suspect or has the potential to fail. Pay attention when you find these and mark the different layers in your backcountry journal and also by creating an indentation in the observation wall itself. It’s also helpful to understand where each layer lies within the snowpack and if it might have the potential to be reactive in the future.  
Here is a good link if you need a refresher on testing layers

Identify the differences in hardness

3
​
Snow Stablility Tests:

Once you’ve identified the layers within your pit and potentially highlighted some that could be problematic, it’s time to test stability and reactivity. The two most common stability tests are a compression test and an extended column test.

• The CT or compression test is a good place to start your stability tests. They are even more helpful if you have time to do more than one or you’re doing a variety of tests over the day as it’s easily repeatable. To refresh your memory, a CT is an isolated 30cm wide x 30cm upslope column.

• The ECT or extended column test is most often the standard to observe the tendency for a layer to fail and propagate. The ECT is a 90cm wide x 30cm upslope isolated column. The width of the column serves as a better observation tool for the probability that a weak layer will propagate and to what extent.

As a refresher, each test consists of 30 total taps; 10 from the wrist, 10 from the elbow, and 10 using the entire arm from the shoulder. It’s helpful to have one person tap while a partner watches for cracking. During both tests, you are looking for a failure within one of the layers and if there is propagation across the entire column with that failure. A propagation suggests the ingredients for not only that layer to fail but for it to fail across a larger area resulting in an avalanche.
As you perform your test note which layer(s) failed, whether propagation occurred and on what number of taps. Record your results as ECT, P for propagation, N for no propagation, or X for no results with the number of taps. For example, ECTP23 means in your extended column test you had a failure and propagation at the 23rd tap. Make sure you record where (how many cms deep) and on what layer the failure occurred, noting the interface.

Taps translate to the force or weight needed for a particular layer to fail which can identify additional red flags. It’s easy to walk away if you’re seeing a clean propagation result after a few taps indicating that it wouldn’t take much to initiate a slide. But, what if you’re getting results on 25, 28 or even 30? It could in some cases (especially if you’ve been tracking a specific layer) indicate that the snowpack is gaining strength over time, which is a good thing. Keep in mind though, a consistent failure at a higher level of force or weight creates the situation where a false sense stability could lure you into larger terrain with fatal results if it fails. This is often seen with persistent slab layers and can be viewed as a potential ticking time bomb. 

No matter what, if a block pops out at you with energy during a stability test (especially if it happens more than once) it’s going to be a low angle pow day. Any failure and propagation that moves with energy is a bright red warning sign that things are primed to go big or even be triggered remotely.

Finally, one test is not enough to give you a full picture of the problem. Note that with additional tests you can verify a repeating result or lack of one like a typical science experiment. That said, getting no result does not automatically mean you’re in the green. Dig on different aspects and elevations to see if there are reactions elsewhere. Always be suspicious.

Snow Stability Tests

4

Results and Next Steps:

​Based on what you’ve observed from your pits and stability results, you should have a better understanding of how the snowpack is reacting in your chosen area. Once again, the lack of a result in one snow pit should never be a green light to ride suspect terrain, but it should give you additional information to support your plan and comprehension of the current snowpack behavior. Next steps would be to document your findings in a notebook throughout the season, continue to dig pits on a variety of aspects and elevations, and use that information to forecast a full picture for yourself.

It’s also never a bad idea to consider a refresher avalanche course or continuing education clinic. Over time standards evolve to more efficient and effective tactics; learning the most up-to-date processes for snowpack analysis helps keep you on top of your game. Not to mention it gives you the opportunity to learn new tricks!

Making Observations

Summary

Although it can feel time-consuming, making the effort to dig snow pits and track problem layers over the season gives you a great idea of what you can ride and when especially in relation to consequential terrain. Do yourself a favor, take a sunny “rest” day and go dig some pits with your friends to see what you find. It’s great practice and you’ll take away a deeper understanding of what you’re either about to go ride or will ride later in the winter.

We have loaded a load more snow pit data for you to look at from the past years .
See link below to view info
​http://www.snowsafety.com.au/conditions.html

My guests had too much energy today. So I made them dig a 250cm deep snow pit!
I wanted to find the fattest snowpack and see how the DPWL was changing. Sure enough we found a 20cm thick Facet layer down 220cm that was alive and well below a solid snowpack. You can see in the photo the hollow where we scooped the loose Facets out with our hands. We didn't do any tests on the layer, but I wanted them to see what we were skiing on. Most people don't fully understand what weak layers we ski on. This is why it's so important to check the avalanche bulletin everyday, even if you plan on not skiing.
Today our main concern was the fresh windslab. The video shows this failure between the old snow and the most recent storm.
Pit data: 
Location: Stormheimfjellet, 
Appearance: planer slope immediately Lee of a ridgeline, large gradual convex roll
Elevation: 800m
HS: 290CM
Angle: 32degrees 
Aspect: E

​Writer (Mike Wigley) and Rowan Bashford skinning up the Mueller Glacier, New Zealand. Photo by: Tess Carney


What to carry in your pack for a tour:

• Shovel, transceiver, probe, collapsible poles, skins
• Goggles, sunglasses, sunscreen
• Lunch, snacks, water
• Map, compass
• Extra layers for when you take a break or emergency
• Extra gloves, hat
• First Aid kit with an emergency space blanket
• Repair kit for splitboard (extra binding parts, screws), screwdriver, (2-4) rubber ski straps (Valhalla Pure), duct tape, needle and thread, Leatherman or multi tool with knife, scraper.
• Emergency device (cell phone, Delorme inreach/ spot SOS messenger, sat phone)

 
Morning Rituals:

• Have your pack set up for touring the night before so you don’t forget anything, double check the list before leaving the house for a solid day of touring.
• Put your beacon on while getting dressed checking battery power.
• Leave skins off skis till you get to the trailhead.

 
At the Trailhead:

• Turn beacon on; check yours and the group member’s battery percentage.
• Set up collapsible poles to your height, with your elbows making a 90 degree angle while holding the pole handles and the ski baskets on snow
• Set up splitboard for skinning. Practice at home to be fast in the field in various weather conditions. For skinning swap the splitboard skis, so the straight inside metal edge is your outside edge while walking up hill. Place skins and bindings onto skis and strap in.
• Delayer clothing so when you start skinning your at a cool temperature.
• Have a member of the group do a beacon check before skinning for the day.

 
While Skinning:

• Take your time, walk at a speed so group members are able to have a conversation without feeling short of breath.
• If breaking trail in the snow, keep the angle of the skintrack low, in the long run it keeps everyone’s energy levels up and is more efficient.
• While leading make sure to know who is on the tail end and periodically look over your shoulder to ensure everyone is together.
• While skinning on the snow, keep the skis on the snow and glide them rather then lifting.
• Use your poles to engage your risers when the angle of the skintrack becomes too steep. Take off risers when angle of skintrack mellows out.

 
Switchovers:

• Practice makes perfect. Practice inside switching over from skis to snowboard and vice versa. Applying skins and taking them off and having a place for all your gear in your backpack mapped out. Makes it easier to organize yourself in the field and recognize if you forgot something.
• Have a routine at the top;
  • Quickly stomp out a spot in the snow to switch over
  • Take off pack and place beside you
  • Collapse poles then place on/in pack
  • Unstrap bindings, step beside
  • Pick up one ski, take off binding and set aside, then take off skin and place on pack. Repeat with other ski. Then taking both skins and placing them in you pack or jacket. Finish putting splitboard together.
  • Grab an extra layer for the ride down, eat a snack, drink water, and a good time to fiddle with any gear before riding down.
  • Put on goggles and helmet, strap into your snowboard in a comfortable spot. You may need to stomp a spot in the snow to strap in.
  • Make sure where you strap in, your able to just roll into your line.
• The above routine can be used for switching over from snowboard to skis as well. I find if you do your switch over first, then you have time to enjoy a break with snacks and water while everyone finishes their changeovers and discusses the plan for the run down or the route up.

 
Extra Helpful Tips:

• If you find your skins are failing on you, pull over and take your skins off. Scrape any snow or ice off the adhesive side of your skin using the metal edge of your skin. Take 5 minutes and put your skins in jacket to warm up glue, to help the glue become more adhesive. If still failing use rubber ski straps or duct tape and wrap around skis and skins to help skin stay in place on ski.
• As well on the ride down you can ride with your skins in your jacket to ensure the glue lasts longer through the day.
• Be mindful of the terrain your splitboarding in and if you should keep your poles out or not. If your designated run isn’t fall line and you have to traverse or rolling over flat sections, keeping your poles out could benefit you.
• Carrying a multi-tool, knife, and a scraper in your pants pockets can save you time on switchovers. If you need to scrape snow or ice off your board, or tighten some screws.
• Learn what clothing layers works best for you in certain climates while touring, to reduce in sweating or getting soaked in wet climates.

 
Enjoy the journey of it all. It’s not all about bagging peaks and slaying lines, it’s about the whole process of connecting in the mountains with friends and loved ones. There’s a lifetime of lines out there to explore, enjoy the moment.

See full article here