nysnø

Nysnø is the freshly fallen snow layer that blankets the ground after a snowfall. It is typically light and loose, with a high degree of porosity, and can cover a wide area depending on wind and terrain.

It forms when snow crystals settle on the ground and compress slightly under their own weight. The grains are often soft and weakly bonded, yielding to disturbance by foot traffic or wind. The layer varies in thickness and density across slopes.

Weathering processes such as warming, melting, refreezing, and wind quickly change nysnø. In cold, calm conditions it may persist for days; warming or rain creates crusts or consolidates the snow. Wind can redistribute it into drifts and wind slabs.

In a snowpack, nysnø provides insulation and affects albedo. It can form a weak layer that becomes a slip plane under new loading, contributing to avalanche risk. Its persistence and metamorphism influence how the deeper layers compact and stabilize the overall snowpack.

The term nysnø is Norwegian for freshly fallen snow and is widely used by meteorologists, snow researchers, and winter-sport communities to describe the top snow layer after a snowfall.