Avalanche control teams in Switzerland’s mountainous Valais canton have brought forward detonations in the region’s many ski slopes to counteract the unusually warm temperatures for this time of year.
Typically the risk of avalanches in the mountainous region increases in March or April, but Switzerland’s Institute of Snow and Avalanche Research (SLF) has decided not to run any risks given that the snowpack in February is already wetter and weaker than usual.
“These changes in the snowpack have arrived a month early because of sunny and warmer weather conditions,” Thierry Meyer, president of the region’s security and patrol team, told Swiss daily Le Temps.
Even though the risk of a dry avalanche stands at 1 out of 5, the chances of a wet avalanche taking place are far higher (3 out of 5), especially on ski slopes to the south of Valais below 2,800 metres.
Avalanche professionals make a clear distinction between dry and wet avalanches as they are triggered by different factors and move differently down the slope.
Usually wet avalanches are caused by rain, prolonged periods of sunshine and higher temperatures, whereas dry landslides are often caused by skiers putting too much pressure on the snowpack.
Wet avalanches also tend to move slower down the slopes (16-32km/h) compared to dry avalanches (around 120 km/h) but still pose a serious risk to skiers.
“Perhaps we’re being over-cautious but these are the worst wet snow conditions we’ve had,” Meyer explains.
“Wet avalanches can happen all of a sudden, so carrying out preventative explosions can increase our chances of success, although it isn’t always effective with wet snow.”
The news come just days after a French ski patroller died after an avalanche struck a ski slope in Valais.