SnowFlurry 1 2017/18 | The essential distinctions

First of all, for our new readers: In SnowFlurry, we don't just rummage through the snow... The priority will be on currently observable processes in snowpack development and their effects on avalanche risk, illustrated with snow profiles and their interpretation. We will often get to the bottom of the matter using models and extreme simplifications or hyperbolic language in order to focus more on the essentials. There will also be a sporadic look at other departments of Winter and Brettlrutschen. At the end of each SnowFlurry, we will find a mnemonic phrase - easy to memorize.

This year, we will use many of the terms from last season's SnowFlurry as a basis and put them into a suitable framework, the so-called "essential distinctions": The essential distinctions for survival are based on empirical values that show which terms are often not consciously perceived and cannot be distinguished or defined. Some of these words appear regularly in the management reports, others are not read there, but without having understood them, it is impossible to grasp and apply the information in the management report.

Knowledge - experience

We make an explicit distinction between knowledge and experience. Knowledge does not replace experience and experience does not replace knowledge. Not only in snow and avalanche science. The last three winters have shown us in the Eastern Alps, for example: When it comes to the old snow problem, a high level of experience is almost useless if you don't have a sound basic knowledge base.

Danger level - danger level

Three is not the same as three, two is not the same as two. The hazard level merely describes the overall situation. It is an average of the avalanche danger on all slopes of all exposures in the altitude range in question. With one and the same avalanche warning level, it is possible that slopes in the southern sector (= exposure west to south to east) are highly dangerous, e.g. in a spring situation. The same danger level also includes the situation where slopes in the northern sector (= exposure west over north to east) are easily triggered by weak layers in the old snow, but the southern sector is safe. Same danger level, but completely different areas are safe or dangerous! It always depends on the distribution and trigger readiness of the danger spots. The level only summarizes them and alone brings us as much as a touring ski without skins.

Hidden danger signs - obvious danger signs

Easily recognizable are, for example, uncovered drift snow packs, sliding snow mouths, soaking of the snow cover or the amount of new snow. Difficult to recognize are old snow problems, i.e. weak layers within the snowpack, but also snow-covered drift snow packs. They are only occasionally obliging and give off settling noises or cracks. Not every danger shows itself in the terrain! Weak layers in old snow can often only be recognized by carefully reading the situation report or bulletin. Other dangers can of course also be read there, but they are much easier for everyone to recognize in the terrain.

Avalanche times - avalanche locations

The central question in personal avalanche management is usually linked to the spatial dimension. It is: "Where can I trigger what?" If the snowpack stability changes massively on a tour day, the temporal dimension is added: "When can I trigger where and what?" We find this primarily in the spring situation, but also in snowfall, rain or persistent wind activity.

Easily manageable - difficult to manage

The distinction between situations ranging from very safe to extremely dangerous brings us to the handling of the individual situations: Situations that are easy to handle, i.e. those in which decisions can be made simply and with less complex considerations, are at the two extremes: In our system, these are the danger levels Low - 1, Major - 4 and Very Major - 5. In the "Low 1" danger level, there are only very few danger spots where it is considered possible that an avalanche could be triggered. For the most part, you can worry about other problems on the tour. You often have to be careful not to fall on hard snow. Due to the high probability of spontaneous avalanches - i.e. avalanches that start on their own and do not require an external trigger - it has become common practice not to leave the secured terrain at danger level "large 4". They are therefore also very easy to handle: through the criterion of "complete abandonment".

The situations in between are difficult to handle; these are described in our system with the danger levels "Moderate 2" and "Considerable 3". Here, the avalanche triggering probability is distributed like a more or less orderly patchwork quilt in the terrain: There are places where triggering is easy, places where triggering is more difficult and places where triggering is considered unlikely. This situation is the most difficult to handle. Completely abandoning the day in the terrain is rarely the chosen option. Partial abandonment of certain areas, areas, altitudes, exposures & slopes is now the chosen remedy. These can be read explicitly from the situation report. In some cases, they can be narrowed down relatively precisely by the avalanche warning system, e.g. to a precise altitude band for the old snow problem. In some cases, they can only be roughly defined. The areas where you have to be more careful or should stay away are more or less known. We don't have to interpret the lines in the situation report subjectively, but take them as they are written and implement them in the terrain. This means, for example: In the event of an old snow problem, at best not go to the area in question at all and if you do, show maximum defensive behavior, in the event of a drift snow problem, avoid the recognizable drift snow, or be back home early in a classic spring situation.

The Schneestöberer wishes you an eventful and accident-free winter!

Note: Becoming aware of which situations you can handle easily and when it is more difficult to practice good avalanche management is a big step forward in your personal development with regard to avalanche risk management.