Planning a Winters Day - Hillwalking


It's getting to that time of year again, temperatures are dropping, the tops of the mountains are starting to show the first snows of the season and what we pack in our rucksacks starts to change. With more factors to take into consideration, we need to start to think more in terms of how we plan our days for the snowy months. A great model for decision making and planning our days comes from the Scottish Avalanche Information Service (SAIS) - The 'Be Avalanche Aware' Model


Using this model gives us a process to work through, making decisions at different stages in our proposed day. Throughout these three stages;

  • Planning

  • Journey

  • Key Places

we take into consideration three factors

  • Conditions

  • People

  • Terrain

We can then apply a simple probability vs consequence scale to aid us in making a decision. Let's put a little more meat on the bones...


Planning Phase


I expect to make around 80% of my decisions at the planning stage. To make an informed decision we need to have relevant and up to date information to base our decisions on. So what information do we need?


Conditions

People

  • The people/person that you're intending to spend the day with. Who has the most experience?

  • Do we have enough equipment individually for our days objectives, ice axe, crampons, enough warm clothes in case we have an unexpected turn in weather or have an accident? Could we sit it out for 4/5 hours without moving? Group shelter? First aid? Shovels, probes? Rope? What maps are we planning to use? I personally use 1:50 format prints out but blow them up to 1:25.

  • Does everyone in the group know how to use the equipment that is in their bag? Are we planning to cover some skills during the day?

  • Have we left a route plan? Does the person who has the route plan know what to do if we don't check in at the end of the day?

  • Even if I'm the most experienced person, I still need to take myself into the risk assessment process. (for example, a niggling injury).

Terrain

  • What are the objectives for the day? Any steep slopes to gain this objective? What aspects are the slopes? Do we need a rope and if so, do we know how to use it?

  • How complex is the terrain? Can we navigate and get the relevant information to travel safely if the visibility is poor? Are we crossing any 'hot spots' that are well known for avalanches?

  • Can we use features that are safer to travel shoulders, ridges, scoured slopes.

  • Fatmap is becoming increasingly popular and is very useful for a visual representation of the steepness of the terrain. It's also free for basic use as described in this blog.


An example


So let's look at an example, applying the above framework to planning a day around the Northern Corries in the Cairngorms. First of all I would look at the weather forecast taking 3 pieces of information,

  • Temperature,

  • Precipitation

  • Wind (strength and direction)

I then tend to have a rough idea of what the avalanche forecast rose should look like. For example with the avalanche forecast below the weather forecast was showing gale force winds West to South West.


The avalanche forecast can seem a little overwhelming at first and for our first few planning sessions, lets keep things as simple as we can. The basic core segments of information from the forecast above are what slopes the snow has been deposited on. This is shown in the example by the orange triangles, indicating that there is a 'Considerable' risk on North, through East to South-Easterly aspects above 950mtrs. A 'Moderate' risk on North-West above 950mtrs. Between 950mtrs and 600mtrs North through East to South-East.

Also the key symbols that are in the bottom left corner; indicating a weak layer within the snow pack; wind slab. Snow developing cornices on steep head walls and corrie rims.

So how can we apply this information to our proposed journey? Below is a rough visual representation of the forecast for our intended route.



As you can see, our proposed day is showing slopes that are highlighted in the forecast as being in both 'moderate' & 'considerable' avalanche terrain. And when we look at the Avalanche Hazard & Advice Table it states for considerable that 'a single person load is likely to trigger an avalanche on some slopes.' A little scary, right? This is where I apply the 3 A's

  • Aspect

  • Altitude

  • Angle

From the map above we can see that some of the suspect slopes are both on aspects and altitudes that we plan to travel over, leaving us with only the angle of the slope to allow us to potentially reduce the risk. So how can we measure this at the planning stage? We can measure the run and rise.



As you can see from the image above,100mtrs distance measured (run) there are 3 contour lines in height (rise). Giving a rough slope angle of 15 degrees. We exclude the first contour line at the start of the measurement as this doesn't have any rise/height. In this particular example I'm using an OS 1:50:000 map blown to 1:25:000 scale that has a standard 10mtrs height per contour.


As a rough guide, 100mtrs in distance with 5 contour lines in height gives around 25 degrees. This is the number I start to have flags raised, therefore not the angle to be on potentially loaded slopes. Most avalanches release between 30 - 45 degrees, and having 25 degrees gives me a little margin for error.

A simpler way to remember the calculation; 100mtrs distance, 5deg steepness per contour line (10mtrs height) on OS maps, as used in this example.

You can be more accurate using a slope angle calculation if you wish!



Fatmap has a great feature for showing the gradient, shown in the image above. It's free to register and use these features. I personally use this a lot in winter, particularly for new areas or if I'm hunting for snow, usually on skis!


Key Places


These are points during our day that we can gather more information and chat as a team on how the day is going, allowing us to make a safe decision. i.e. Do we continue or turn back? Do we have enough time and energy to summit the other Munro? What are the current conditions? Do we have visibility?

Some thoughts and details below on each key place. Although we are planning these places, they will also be part of our journey phase. I only expect to make around 5% of my decisions at key points as we have a strong but flexible plan and will be gathering information on the journey to each key place. The thoughts behind this are that we don't corner ourselves into making a poor or rushed decision.



Key place 1 - When we arrive at the car park

Are the conditions as we were expecting? Snow level? Visibility? Everyone feeling OK? Has anyone forgotten anything? Can we see what effect the wind, temperature and any precipitation has had on the slopes? Are the ground conditions what we were expecting? Do we need to chat through other options?


Key place 2 - Gathering information

How are the conditions underfoot? How long has it taken to get to this point? Are our objectives for the day achievable? Can we see our route and what the conditions on the ground are?


Key place 3 - Gaining height

How are we doing for time? Moving well? How does the North-West slope look? Icy? Windswept? Snowy? Do we have visibility? Is it what we were expecting to see? Do we have the equipment to tackle the conditions?


Key place 4 - Cairn of 1141

Are we planning to summit Cairngorm? How are we doing for time? Energy levels? Morale? Weather? Head down to the car park from here? Is is safe? Straying onto the steep Northerly slope of Corrie Cas would not be a good place to stand in the current forecast.


Key place 5 - Ptarmigan restaurant

Can we get some shelter? Food stop? Follow the piste/lifts down if there is bad visibility or head down the ridge for better views?


During all 3 stages, planning, journey and key places, it has been proven to show that when all members share observations, thoughts and ideas it can help to come to a safer and more rounded conclusion for the group.


Journey Phase


I expect to make around 15% of my decisions during this stage. If you're staying close to the start of the route (in this example Aviemore), This can be as early as stepping out of the door. Is it snowing, cold, windy? When I arrive at the car park, temperature? Warmer/colder or as expected? Is the wind blowing as forecast? Strength & direction? Is it snowing/raining/clear? If we have visibility, are the slopes looking as expected? Some aspects scoured and lee sides white with wind slab. Any fresh snow?


When walking from the car park to key place 1, what are the conditions underfoot? Any fresh snow? Is everyone moving OK? Any equipment forgotten? Does this affect our decision making? Can we see if there has been any avalanche activity? During my journey I want to see and feel the snow/conditions, this might feel a little jedi but this is what we are aiming for, being able to improve our situational awareness from as many of our senses as possible. As we've mentioned we need information to allow us to make better decisions. I find that Colour, Shape and Sound work well i.e. windslab, the most common type of avalanche in the UK (we do get a lot of wind...) is when snow blows the lovely snow flakes against each other to make more rounded grains which then land on the lee side of the mountain. Like sugar waiting for just the right amount of weight to release the slab. Windslab looks chalky and duller than fresh snow, it can also be squeaky when stepping. The shapes of sastrugi or rime can tell me which way the wind has been blowing. Is the snow cracking underfoot? Not a good sign! Any evidence of any recent slides? Are there people operating in areas above us that might be an issue? Are they on loaded slopes? All of these bitesize segments of information are what we use at our key points.



Even with all of this planning and good judgment, at the end of the day, accidents happen. Whether I'm working or on days off I leave some details on a 'Check In' Whatsapp group as follows. It has clear details of where I'm going, usually a screenshot of the map. Details of when we meet, potential changes of plan, details of all in the group i.e. phone numbers, medicals, age etc. and a process to work through if no contact can be made. There have been a few mountain rescue call outs to find people safe and well in the pub. Having a check in procedure will provide peace of mind both for the person potentially calling the rescue services and yourself that if we can't get help on our own, someone at home will alert mountain rescue and help will come.



Summary


We will inevitably learn lessons, sometimes hard one's. What's important is that we learn from them and that it's OK to make mistakes. Just don't let them add up or pass you by as 'that was close' but we made the right decision because we didn't have an accident.

  • Plan

  • Do

  • Review

The simple model gives us the opportunity to review our days, good or bad. Where did it go wrong? Where did we make a mistake? During the planning phase? Day too ambitious? The group didn't have enough skills or equipment? Did we miss key pieces of information during the journey phase? Did we use the key places? What went well? Timing? Planning? Decisions that we made? Did everyone have an enjoyable day? A great outcome for me is that we had a safe day, learned something new and people have some fun along the way!



If you have any questions, thoughts or if we can help with clarification of anything in this blog feel free to leave a comment or get in touch.


This blog is designed to help people have a tried and tested method of planning days and is no substitute for proper training and experience. It is intended to be used to aid or help people have a clearer understanding of how to have a safer and more enjoyable time in the mountains.


If we can help with any training, feel free to drop us an email on info@scottishrockandwater.com or check out the website for our Winter Skills Courses



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