The transformation of snow is called Metamorphosis. The snow begins to transform practically as soon as it hits the ground. Still, the speed depends on many factors like temperature, wind, temperature variations in snow depth, humidity, precipitation, solar radiation, salting, and machine prepping. 

Fresh snow is fresh until a change occurs. Wax techs and meteorologists often have different views on what fresh snow is. For ski technicians, it depends on how long the snow has been untouched at a stable temperature, but it is the snow that falls here and now for meteorologists.

Felix Breitschädel is responsible for Olympiatoppen and works with friction between skis and snow. He is a key person in developing sports technology aimed at priority sports at the Olympiatoppen.

“Fresh snow often shows sharp shapes. It can be anything from long thin rods to perfect hexagonal shapes and 1000 other shapes.” 

“This snow that lies untouched and falls during a prolonged cold period is usually relatively dry, and it takes a long time before it is transformed,” says Felix Breitschädel.

“The new snow lasts for about 1 to 3 days. After that, they talk about transformed snow. Once the snow has been transformed, a distinction is made between finely transformed or coarsely transformed snow. With below temperatures, the snow changes quickly. The snow conversion goes faster when there are plus temperatures in the air; the snow crystals lose their pointed edges and are transformed into round shapes.”

“The snow crystals transform and change in steps with different cycles of plus and minus degrees. With such temperature changes, a lot happens with the ski tracks, and the changes concerning which ski wax to choose are large.”

“Typical ‘Easter snow’ consists of coarse-grained, round snow crystals,” says Felix. “It has become more and more common with winters where it changes between minus and plus degrees. If there are ski races in the evening under relatively mild temperatures and it freezes during the night, you get fast and steady conditions the next day.”

• The proportion of free water in the snow increases during the plus temperatures; in other words, the humidity in the snow has increased.
• With minus degrees, the snow crystals will freeze together again. This looks very good when a ski track gets through the night. This is called in technical language, sintering. Artificial snow and natural snow transform differently. Artificial snow has different properties than natural snow—the snow crystals in artificial snow change differently from ordinary snow.
• Artificial snow is water droplets that freeze outside and then inwards. Natural snow begins in the middle and grows outwards.

“How the natural snow transforms and how fast it changes still depends on humidity, temperature, and how fast the snow falls, to name a few,” Breitschädel explains. 

“A mixture of artificial snow and natural snow often becomes a mix of quite different snow crystals. The artificial snow is often aggressive. It is often angular and tightly packed, which is quite hard and wears the ski base. The humidity determines how the artificial snow and natural snow will mix,” Felix concludes.