European Avalanche Danger Scale
So we are all avy-savvy travellers. We follow the state of the pack throughout the season, and we check the latest avy forecasts before we go. Avy forecast says "considerable"... or was it "moderate"...? Well what does that actually mean. As with much of our back-country recreation it straddles the thin line between science and dark art.
The EAWS (European Avalanche Warning Service) has done much to move that line from the darkness towards science. Have a look at the danger levels and the implications below. Make sure to note the distinctions between terms like "steep" and "moderately steep"
It is also very important to understand the frequency and range of risk for a given danger level. From the EAWS site:
In nature, however, the avalanche danger changes continuously and rises disproportionately. Therefore the avalanche danger can have very different characteristics within a danger level. This range is most apparent at hazard level 3-Considerable. At the upper limit of this danger level many alarm signs are observed (whumphs, shooting cracks, fresh avalanches) and the danger is very present. At the lower limit of this danger level these clear indications are missing. Often – mostly unconsciously – this leads to riskier terrain choices.
FREQUENCY OF DANGER LEVELS
In the assessment area of the avalanche.report, danger level 2-Moderate is forecast in almost half of the days (per warning region). This danger level is most frequently used. It thus describes a day with average avalanche danger. Level 3-Considerable is issued on about one third of the days. This is where most fatal accidents occur (approx. 50%). The danger level 4-High is issued on average only on 2% of winter days, i.e. on approx. 2-4 days per season. Level 5-Very high is reserved for castrophic situations and is therefore rarely used.
To get the whole picture and understand the subtleties of the danger scale, grab a coffee and read the article below. 10 min that could save your life one day...
If you are still want more - lots more fascinating info at the link below