WHY FRESH POWDER SNOW DOES NOT GLIDE AT ALL?

 Why skiing on fresh powder snow is so challenging?

Fresh powder snow or freshly fallen snow at temperatures below zero and low relative air humidity is extremely challenging for gliding and low friction coeficients.

Why?

Powder snow is cristalic, in other words: individual snow flakes keep their original sharp shape. If they brake during slope or track preparation by pisten bully new sharp edges, tips and forms arise. 

Powder snow contains a high share of air resulting in surface changes of the snow if skis are gliding over it. Such surface changes lead to brittle deformations of cristals again.

Result:

Sharp, hard, brittle snow cristals which brake and do not connect to snow pack. The surface of the snow is extremely fragmented - similar to a stone field resulting in few and very small contact points between snow and ski base surface.

Few and very small contact points between snow and ski base surface lead to high pressure in the contact spots. Small contact points, high pressure, sharp / hard and brittle cristals create a combination responsible for very high friction between snow and ski base surface.

The lower the temperature, the higher the hardness of snow cristals. At a certain point (for normal ski base types = HDPE at ca. -10 degrees C, for competition ski base types = UHMWPE at ca. - 15 degrees C) the hardness of sharp cristals exceeds the hardness of the ski base resulting in ski base plowing effect.

Under such conditions you will not want to ski...

Conclusions:

If fresh powder snow is fallen deep below zero, stay at home instead of skiing! If you need to ski in fresh powder snow on a slope, protect your ski base with a hard and hot applied wax coating. If you are a nordic skier, protect your ski base and try to improve the gliding properties the best possible way otherwise your trip can turn in a nightmare - apply hard protecting wax hot with a hot powder coating and liquid speeder!