The Swiss Federal Institute for the Study of Snow and Avalanches has reported that avalanche deaths for the 2006-07 winter were well below average. Avalanches claimed 7 off-piste skiers, 6 ski tourers and 1 other person. No snowboarders or climbers have been killed to date. The figure is well below the long term average of 25 deaths.
The winter was the warmest ever recorded by the Swiss Weather Service with precipitation over the October-April period below average. In the North and West snow cover was practically zero below 2000 meters with some of the lowest figures on record recorded both in terms of depth and length of cover. It was only in rare cases and then just for a limited time that snow depths reached the long term (since 1945) average. During the weather system associated with the hurricane Kyrill on the 19th of January it even rained to 2700m. At high altitude maximum snow depths were reached in March, a month earlier than normal. The thaw in April was very rapid, spring was 2 to 4 weeks early. In short a winter of extremes: late and poor snow coupled with high temperatures.
Generally the snow pack was stable, especially during the second half of winter. Fresh snow and violent winds from the west and rain to 2500 meters overloaded the snow pack and resulted in a number of High avalanche risk days, particularly in the west. Between these episodes humidification at mid-altitudes and high winds at altitude helped stabilized the snow-pack over much of the country.
The situation was different in the inter-alpine regions, for example the Grisons were protected from westerly gales and experienced cooler temperatures. Even if the avalanche risk never reached High the fragile snow-pack created tricky avalanche conditions. There were incidents caused by slab avalanches throughout the winter.
Overall the SLF recorded 111 avalanches involving 197 people. There were 15 deaths, 35 injuries and 20 avalanches caused damage to infrastructure. These good figures have a number of causes.
1. The warm weather and rain at altitude helped to stabilize the snow-pack.
2. Poor snow cover, particularly until the New Year, severely restricted any off-piste skiing and ski touring.
3. The publicity about poor snow conditions in the mainstream press meant that less people overall visited the mountains.
The SLF also hopes that their education programmes have had a positive effect on the behaviour of backcountry travellers.
