On 28 January 2021, the avalanche risk reached level 5, the highest rating, in parts of the Switzerland. The authorities in the canton of Valais have advised residents to limit their movement.
WSL, the research institute that monitors avalanche risk in Switzerland, warned on 28 January 2021 that some parts of the Swiss Alps were at Level 5 avalanche risk.
Level 5 risk (zones in dark red) is very rarely forecast and is described as an extraordinary avalanche situation. Numerous very large and extremely large natural avalanches can be expected, which can reach roads and settlements in the valley, said WSL.
The WSL avalanche risk map was updated on 29 January 2021, with the highest Level declining to 4 (red zones in image below), a level described as a very critical avalanche situation where natural and often very large avalanches are likely. Avalanches can easily be triggered on many steep slopes. Remote triggering is typical. Whumpf sounds and shooting cracks occur frequently.
The high central Alpine region stretching the width of Switzerland is at greatest risk. Avalanche risk in this region is at Level 4 anywhere above 1,800m, said WSL. The avalanche risk across the remainder the Swiss Alpine region is Level 3 and the risk in the Jura range and part of Ticino is Level 2.
According to WSL, there are large amounts of fresh snow and freshly generated snowdrifts that are extremely unstable. These layers have been deposited on top of weak old snowpack. Persistent rain and and mild temperatures will perpetuate very high avalanche activity and isolated extremely large avalanches are possible, it said. Below 1,800 metres the snowpack has been weakened by intensive rainfall in the northern and western regions of Switzerland in particular.
According to RTS, several train links were cut by avalanche activity. The link between Zermatt and Täsch was disrupted and the train between Haut-de-Caux and les Rochers-de-Naye above Montreux was stopped. A 19-year old recently perished in an avalanche in the same region.
Residents in the commune of Orsières near Verbier were asked to evacuate on Friday afternoon, according to Le Nouvelliste. Avalanche exposed buildings were evacuated on the Neuvaz plateau, the hamlet of Granges and the village of Ferret.
WSL advises against ski touring, snow shoeing and off-piste skiing.
Cantonal authorities in Valais recommend limiting movement, respecting warnings and avoiding avalanche risk areas (avalanche corridors), even where avalanches have already fallen. Other avalanches can occur on top of existing ones said the cantonal police. Any excursions off piste should be avoided until further notice, it advised. Some communes have issued similar warnings.