EUROPEAN AVALANCHE DANGER
The European risk scale for the
avalanches includes 5 levels defined by an assessment of the stability
and its consequences in term of probability trigger avalanches. None
of the risk indications is to disregard. In mountain, risk 0 doesn't
exist and the danger whom skiers, snowboarders or pedestrian exposes
itself, grows as well as the value of the indications. The avalanche
risk is not a measurable parameter; every indication of the scale
translates not what is going to happen, but what can happen with the
best probability, considering the analysis of the situation and the
knowledge. You can find the flags at the departure and the arrival
of main ski lifts and news-bulletins are at different information
points.
| European risk scale |
Stability of the mantle of snow |
Signification of flags |
| Low risk |
Generally stable snow,
so the conditions to practice the mountain sports are favorable. Isolated
areas of instability like in strong declivity sectors or in crests and
pass having slope ruptures. Trigger risk is not considered in must of
cases but under the strong overcharge effect. Small avalanches or streams
represent natural trigger. |
 |
| Moderate risk |
The general stability
is satisfactory but localized instability affects some slopes whom the
exhibition and the altitude are often mentioned. Trigger risk concerns
only few slopes. Not very dangerous but under strong overcharge effects
(a skiers group, for example). Spontaneous trigger risk is not very
important. Streams or avalanches that can occur are, in must of case,
small size. |
| Considerable risk |
The instability worsens
and involves a lot of slopes of which the topographic particularities
are often described on the news-bulletin. According to the situations,
most exposed areas could be mentioned but remember that the reality
of the land, notably after blown snow episodes, excludes a strict localization
of the sectors. The instability is marked enough and so trigger can
occur just by small overcharge effect, as the passage of only one skier.
When natural trigger is foreseen, this only means few avalanches, only
some of them can be bigger. Somme material damages can happen remaining
exceptional in this kind of situation. |
 |
| High risk |
The instability affects
most slopes, whose features can be signaled in the news bulletin. In
many sectors concerned by this instability by weak overcharge (passage
of only one skier for example). If the accidental trigger risk is always
strong and preoccupying, it is not the same thing when we talk about
trigger risk. Indeed the indication "4" described very different snow
situations and the risk of spontaneous triggered avalanches can be strong
or little marked or even very weak. These nuances are indicated in the
news bulletin. |
| Extreme risk |
The instability of
the mantle of snow is very strong and generalized. Very active, cold
and blown snowfall episodes, brutal warming up and rain affecting a
transformed mantle of snow… numerous and thick avalanches can occur
and can reach some gently sloping area (lower than 20°) Some situations
covered by "5" risk presents a character of exceptional gravity. In
human or material level, consequences can be very serious when big size
avalanche occurs. Pylons, buildings and roads can be damaged. In preoccupying
cases, special news bulletins are given out toward the regional and
departmental services of security as well as toward the media ("avalanches"
regional weather report alert, weather press release). |
 |