The burden of the second and final lecture fell to Alexander Prokop, who is well known both at Snow&Safety and on the Arlberg. Prokop is a lecturer in snow and avalanche research. He leads numerous international research projects in the field of avalanche safety at the universities of Graz and Vienna and has also been conducting research on the Arlberg for a long time.
His lecture was entitled "Snowy versus snow-poor winters - when & where does the avalanche danger lurk?". As an introduction, and thus as a clever link to the last two snowy winters with the special precipitation events, he pointed out that the jet stream has changed structurally due to the strong warming of the Arctic (+5°C in the last 100 years in Spitsbergen). Due to the lower temperature, the stream is meandering more strongly, which means that weather conditions - north jams or sunshine - generally last longer. He demonstrated the very different winter patterns - little snow vs. lots of snow - using the very different seasonal graphs from a snow measurement station in the Lech ski area. Didactically reduced to the essentials, Prokop conveyed the characteristics of the respective winters:
rich in snow = mainly drifting/fresh snow problem, as well as sliding snow
>>> short periods with high avalanche risk
poor in snow = old snow problem
>>> longer lasting avalanche problems
>>> rather large avalanches resulting from the shallow weak layers
>>> rather little sliding snow, rather long periods with unfavorable conditions.
He referred to experiments from his scientific practice, which showed that only round, decomposed snow can absorb a lot of moisture. Large, angular crystals, such as those found in low-snow floating snow winters, absorb almost no moisture, which also explains the lower incidence of sliding snow avalanches
Looking back at the last snowy winter in the northern Alps, he also discussed the avalanche accident in Lech and referred to the FACETs to sharpen your own perception before and during the tour/freeriding. All in all, the two lectures were perfectly balanced this time in terms of length, content and the mixture of new insights and the transfer of fundamental knowledge. The lack of a discussion round was not really missed.
Conclusion
Despite the rather difficult weather situation with wind and poor visibility, these were once again instructive days on the Arlberg. For next year, we can only hope that the free guiding sessions for young people will be included in the program again. PS: There was even a fine snowboard team with Chris Schnabel as guide. So snowboarders as a dying species are also catered for!
