Posted on: 2021-01-28 09:31:20 by davidof

French Alps Placed on Avalanche Alert

All the snow professionals, be they guides or instructors, mountain leaders or resort employees working in the mountains, forecasters, rescue workers, avalanche experts, are sounding the alarm. The conditions are particularly dangerous at the moment. The snowpack is unstable and fragility concerns all exposures.

The recent series of avalanche deaths should make everyone stop and think, as should the announcement of Météo-France placing the departments of Savoie, Haute-Savoie, Isère and Hautes-Alpes on an Orange Avalanche alert.

The National Vigilance Bulletin published yesterday by Météo-France is alarming:

The phenomenon occurs on average once every 4 years or so for the situation late Thursday afternoon in Savoie and Haute-Savoie, every year in Isère and in the north of the Hautes Alpes. The situation is expected to worsen on Friday in high altitude areas.

Current situation

Rather thick snowpack at low altitude with a layer of powder snow on the surface and deep fragility fairly widespread in the interior mountain ranges. After a respite yesterday Tuesday, new snowfall restarted on Wednesday morning in the northern Alps and the northern Hautes Alpes.

Expected evolution

The snowfall will continue and intensify with a gradual rise in the rain-snow line over the Prealps (from Vercors to Chablais), much slower in the interior massifs.

Initially, spontaneous avalanche activity will be mainly due to rain, first low-level slope slides then avalanches, first small and then increasingly voluminous. At higher altitudes, powder snow avalanches will be added, carrying fresh snow as well as recent snow that has fallen in recent days. During the day on Thursday, especially in the afternoon, very large avalanches are likely to take away all the recent snow and sometimes also a significant thickness of the snowpack. An isolated departure of a large-scale avalanche, carrying almost the entire thickness of the snowpack, triggered on a north slope at more than 2300 m approximately, cannot be excluded.

This avalanche activity can reach roads exposed to avalanches as well as possibly the most exposed dwellings (mainly at altitudes little affected by rain). This risk concerns above all the mountain ranges that receive the heaviest rainfall.

The avalanche situation could worsen on Friday morning as the precipitation continues and its intensity increases late at night from Thursday to Friday.