Avalanche risk asssement for backcountry travel is by no means an excact science, due of course to so many variables. We can reduce the risk and the exposure to the risk with careful planning and training. The Euro Avalanche danger scale is a simple and clear guide to the conditions and stability, remember avalanches can and do happen at any point on the scale.
EUROPEAN AVALANCHE HAZARD SCALE(For people skiing off-piste)
DEGREE OF HAZARD -SNOWPACK - AVALANCHE PROBABILITY
1 - LOW The snowpack is generally well bonded and stable.
Triggering is generally possible only with high additional loads  and few very steep extreme slopes. Only a few small natural avalanches (sluffs) possible. Generally safe avalanche conditions
2 - MODERATE The snowpack is moderately well bonded on some steep slopes otherwise generally well bonded. Triggering possible with high additional loads  , particularly on the steep slopes indicated in the bulletin. Large natural avalanches not likely. Basic avalanche skills require
3 - CONSIDERABLE The snowpack is weakly bonded in most steep slopes .
Triggering possible, sometimes even with low additional loads  . The bulletin indicate many slopes which are particularly affected. In certain conditions, medium and occasionally large-sized natural avalanches may occur. Expert avalanche skills required
4 - HIGH The snowpack is weakly bonded in most steep slopes .
Triggering probable even with low additional loads  on many steep slopes. In some conditions, freqent medium or largr-sized natural avalanches are likely. DONT GO
5 - VERY HIGH The snowpack is generally weakly bonded and largely unstable.
Numerous large natural avalanches are likely, even in moderately steep terrain. DONT GO Avoid all avalanche terrain
NZ avalanche scale and definitions.
A simple and effective way to interpret the rating scale:
Avalanche hazard evaluation and forecasting
(Snow safety professionals use some of the information below to forecast snow stability)
Avalanche hazard evaluation relies on evidence from a range off different sources. The weather past-present-and future for example provides useful information. Some information might indicate the snow stability in a very clear way, like ‘present avalanche activity’ some evidence is less obvious, like the past – present and future effects of ‘the wind’ which alone fail to provide enough detailed information. For this reason the evidence is split into three evaluative factors. Class 1,2 & 3.
Class 1 – Where the most obvious evidence is found, evaluation based on evidence in this category is easier to interpret. Present avalanche activity means ‘Danger right now’
Avalanches past and present (Look for both)
Slope testing – Rushblock test
Cracking or slope settlement (Whoompf sound)
Class 2 – Evidence is found by digging in the snow and testing
Slope use and compaction
Class 3 – Evidence is based of meteorological factors
Evidence of instability from Class 1 factors means ‘DON’T GO’ evidence from class 2&3 require more thought and attention.
BCA show us some top tips for beacon searching and digging below:
Every ski area in the Chamonix Valley has a ski patrol and avalanche safety information posted at all main lift stations
We recommend off-piste skiers should be well informed about current weather, snowpack and avalanche hazards. Backcountry skiers should never travel alone. All members of your group should wear a transceiver (457kHz) and know how to use it. In addition to your transceiver everyone should also carry a shovel, and a probe. Backcountry skiers should advise someone of where they are traveling, and when they will make next contact.