Even one of the world’s most experienced World Cup organizers can struggle to provide good snow conditions.  World Championship and World Cup organiser Oberhof received complaints about pebbles and dirty snow on their courses when the biathlon venue opened for training the day ahead of the first scheduled World Cup competition this past week (4-7 January).

The weather in Germany has been completely opposite from the snowy and cold weather in Norway in recent days, and has instead had many days of mild weather, rain, fog and wind.  The organizer therefore had to bring in stored snow, and pebbles and dirty snow became an issue for both skiers and wax technicians.  We have also seen pebbles on race courses in Norway, and several volunteers have had the experience of walking around the courses with spoon in hand to pick up sharp things that ruin the athletes’ skis.

It is especially the combination of a too thin layer of snow on the courses and rain with subsequent high humidity that often creates high melting.  If the thickness of the snow on the course is about 40 cm or more, rainy weather is not the biggest problem as long as the humidity is low enough for evaporation to occur.  Evaporation (either during the day or at night) gives off heat so that the snow layer left on the course freezes over.  If, on the other hand, the humidity is close to 100% (as it is when there is fog) the snow layer will not freeze at all (and will continue to melt).  Even salting will not harden the snow when the humidity is 100%.

Heat from the ground can also eat away at the snow, especially where drainage is not optimal or if there has been no frost. To reduce heat from the ground, insulation mats can, prior to the winter season,  be laid down below 10 – 20 cm of sand or similar.  This has been done in connection with new roller ski courses in Finland (see https://www.snowsecure.com/en/storing-snow-for-xc-skiing).

When snow has to be transported from storage, it is of course important that the snow does not include pebbles and the like.  This is avoided if the snow storage pile is built on clean asphalt, and that the machines and vehicles are washed before use and do not pick up dirt on the roads.  In Granåsen, Trondheim, the stored snow is first transported to and temporarily stored on the paved stadium, where separate and “clean” vehicles transport the snow from the stadium and out along the roller ski slopes.

Oberhof has access to several snow deposits, and has previously also reused the snow from the World Team Challenge at the Schalke/Veltins-Arena football stadium held between Christmas and New Years.

Oberhof is one of the world’s best year-around venues for cross-country skiing and biathlon, with an impressive snow tunnel (see Thuringia Skisport-HALLE) where the temperature can be adjusted so that grooming and the snow is perfect every week regardless of the weather conditions outside.