This Basecamp article is a guide on how to plan a ski tour, to help you in the decision-making process and assessing of a chosen ski tour, and to minimize risk. In addition to the planning stage back at home and assessing the situation in person and throughout each stage of the tour, we will also look at the factors of ‘conditions’, ‘terrain’ and ‘people’, and the influence they can have.

In order to consider and analyze all influences and factors and draw the right conclusions, you need a sound knowledge of weather and avalanche conditions, terrain characteristics, routes, group dynamics and the use of safety equipment. A structured approach and clear rules avoid mistakes, minimize risk and increase safety. For this reason, a standardized approach to avalanche risk assessment has been established.

Effective tour planning is the foundation of a successful and safe experience in the mountains. Since at this stage, we are not usually armed with observations from the actual terrain, we must refer to the data we do have in selecting our area and route. In addition to maps and guides, these are mainly the weather forecast and avalanche bulletin for a specific region.

• What has the weather been like over the last few days?
• What is the weather forecast for the day?
• What do the temperatures tell us?
• What is the avalanche danger level today?

The reported avalanche danger level gives us an initial point of reference and a general overview of regional avalanche risk. On a scale from 1 to 5, the avalanche danger level is indicated according to the following parameters:

• The probability of an avalanche,
• the spatial distribution of danger areas, or
• the size and frequency of expected avalanches.

Variations or combinations of these input variables determine the avalanche danger level. Avalanche risk rises from Level 1 (low) to Level 2 (moderate), 3 (considerable), 4 (high) to 5 (very high) but not in a linear fashion. Avalanche danger usually increases exponentially (i.e. level 3 is not simply one level higher than 2, but possibly twice as high).

Source:
https://lawinen.report/education/danger-scale

The location of danger spots is ascertained through slope aspect (orientation) and elevation information. This allows the orientation and topography of the planned tour as described in the guidebook to be checked again and, if necessary, an alternative tour selected. To recognize danger spots, any crux locations must de marked using the 30° inclination method and then decision-making locations determined along the route. This involves marking on the map all slopes that are steeper than 30° along or above the route and identifying them as potential avalanche terrain. If remote triggering or natural avalanches are not likely, then neighboring slopes above the planned route can be deemed suitable.

In addition to the ‘conditions’ and ‘terrain’ categories, that of ‘people’ is another important one when it comes to planning. Here, we refer to the size of the group and their level of ability (technical and physical), their motivation (family ski tour or freeride pow chase) and their equipment, which also have a bearing on perception of danger and tour selection. The whole group must also be fully aware of the level of risk and agree upon it, and demonstrate adequate risk management abilities.

Once the above steps have been followed and a tour route has been agreed upon, it is a good idea to plot the route, along with any crux or decision-making positions, onto a paper map or using an online planning tool like White Risk or Fatmap, so that you can refer to it during the tour.

Once you’ve decided on a route, the next step in assessing risk is the localized or on-site assessment. This is where you compare the data from the avalanche bulletin danger level information with the actual conditions in the field. And this is not just done once, but on a ‘rolling’ basis throughout the day, because conditions can quickly change. A rolling assessment also of weather conditions, terrain, ability and group participant status is essential too. These on-site observations can lead to deciding on an alternative route, or even breaking off the tour. Again, the DCMR system guides this process.

Where the ‘people’ factor is concerned, frank communication is key. Discussing the forecast from the avalanche report, observed conditions, terrain assessment, partner checks (avalanche beacon), and clear communication about measures that can be taken, and personal responsibility are other essential, possibly life-saving elements. This is the only way to promote better knowledge and risk awareness within the group and to ensure better safety.

Throughout the ski tour, each individual slope should be assessed according to the DCMR system. This is where a final assessment is made of the risks, ski track trajectory and safety measures, through to possibly abandoning the tour. Depending on experience, knowledge and inclination, there are also further decision-making options.

For more experienced backcountry skiers who, in addition to recognizing and understanding basic snowpack patterns, also have some basic knowledge of snow analysis and are competent in assessing snowpack stability, there are other options, such as carrying out a snow pit or stability test to assess the current slope conditions.

Ben Reuter is a mountain guide, snow researcher and deputy head of the avalanche warning service at Météo France as well as a deuter ambassador.