SnowFlurry 24 2016/17 | Ausgestöbert

Natural layer

The first season with the SnowFlurry characterized by some basic education, especially in terms of weak layer formation and the old snow problem. The snow flurries were intended to provide a little more understanding of the fact that snow slab avalanches occur due to a fracture in a weak layer, followed by the sliding of the weak layer and snow slab on a harder sliding surface (an underlying layer of snow or, in the case of a weak layer on the ground, the ground itself). Once you have understood this process, you will also understand why sliding snow avalanches can never be triggered by an additional load - here there is no horizontal "breaking" but only "sliding" - and snow slab avalanches that slide on the ground are not the same as sliding snow avalanches.

We have also spent more time on the build-up transformation. Weak layers can be formed by build-up transformation, i.e. by angular crystals, deep rime = floating snow or surface rime - which can be recognized together by their facet formation and which are only formed on the snowpack or in a snowpack. In addition, fresh snow or sleet can serve as a weak layer, i.e. snow forms formed in the atmosphere. Weak layers, which are formed from crystals of the build-up transformation, can cause problems for much longer - or, as was the case this year, for almost the entire winter. Weak layers whose crystals were formed in the atmosphere are usually only problematic for a few hours to a few days, depending on the general conditions: primarily depending on the temperature.

Both types of weak layers are characterized by a steady increase in the size of the crystals or snow grains during the formation phase and thus by fewer contact surfaces with each other and a higher proportion of air. You can differentiate between atmospherically formed weak layers and weak layers that have undergone constructive transformation by their "color": Constructive transformation = glassy, atmospherically formed weak layer = pure white.

We have heard little about subsidence, also known as degradative transformation, but towards the end of the season we have heard a lot about melting transformation and its effects on snow sports when forming firn. In this context, we have emphasized several times that the compatibility between the slab and the weak layer must be right in order to trigger a slab avalanche.

Finally, here are the key points from 2016/17:

The avalanche risk depends on the conditions prevailing here and now, not on the calendar day or the time of year - especially in the high Alps!

Knowledge is no substitute for experience and experience is no substitute for knowledge.

One cow makes a moo - many cows make trouble.

The snowpack is constantly changing, its condition is never at rest, not for a second.

During long periods of fair weather with little wind in early winter, the danger tends to decrease - new snow is usually followed by a sudden increase in avalanche danger that can last for weeks.

Reflective thinking (What am I doing well? What am I doing wrong? What am I doing wrong? Where is there potential for improvement? How can I improve something?) & Being on the road with open eyes & learning from others can simplify many things.

Snow is porous, hot and transformable. The transformation of snow is always related to the temperature within the snowpack. Snow slabs are created by a fracture and the propagation of fractures in the snow structure.

Tour planning with station data requires a lot of experience, but you can acquire this yourself. One value alone is of little to no use - the combination of several has great significance.

Non scholae sed vitae discimus - or with reference to the mountains: A course or training is not enough, you have to develop yourself and deal with the subject yourself in order to learn enough for survival. Even the highest quality training such as a mountain and ski guide is not enough and can only provide a broader basis. There are avalanche situations that are relatively easy to assess (whether safe or dangerous conditions) and situations that are difficult to assess and require defensive behavior.

The conditions are still unfavorable: The causes have shifted from pure lack of snow to hidden stones and avalanches - good conditions come in March at the latest, winter has only just begun.

Large differences in hardness between snow layers are a negative factor. An inhomogeneous snow cover has greater tension and is considered more dangerous.

Old snow problems require defensive behavior. We consistently avoid steep slopes in the exposures and altitudes that the avalanche report associates with old snow problems.

Reading snow profiles is not rocket science. Interpreting them and drawing conclusions for practical use is more difficult. For the layman - and thus most winter sports enthusiasts - snow profiles are interesting in terms of understanding the process, less so for tour planning or for their own risk assessment.

Snow literature on rainy weekends is almost as awesome or, as they say in the widths of the Schneestöberer: casual as a bluebird powder day.

From the perspective of the future, we are all unconsciously incompetent. Unfortunately, from the current state of knowledge, far too many are also Unconsciously Incompetent. It is up to each individual to at least raise themselves to the level of conscious incompetence.

The avalanche risk in existing tracks may be higher than before the tracks were created, because some bindings have already been destroyed but there are still just enough to prevent break propagation and thus an avalanche. At the very least, the same skepticism should be applied to lightly tracked terrain and little-used ascent tracks as to untracked terrain.

The significance of altitude data for the spread of avalanche problems is relatively high. The problem areas can be narrowed down very precisely in many - but not all - cases, especially with regard to the distribution of weak layers that have been converted by building up.

Wind (with fresh snow) is the easiest avalanche-forming factor to recognize - but is also responsible for the majority of avalanche accidents. Anyone who regularly visits the same areas should become familiar with the effects of the different wind conditions for the respective area.

We can control what is presented to us on the internet with our own attention.

The highest priority is the distribution and necessary trigger load of the danger spots. The danger level is only a summary of the points mentioned; on its own, the level has the same effect as a touring ski without skins - only on the piste.

The humidity has the same influence as the temperature, as it has a strong impact on the radiation in and out. In spring, there doesn't necessarily have to be an avalanche spring situation with a pronounced, diurnal increase in danger.

Whether ribbed, lubricated or studded - there's something for everyone, including snow.

The transitions between all types of snow are fluid, classifications with sharp boundaries only exist in our heads.

Remember: Remember the mnemonics.