Snow Snow Snow can fall in many different forms, but in general it is usually some variation of the classic six arm flake. It usually snows in fairly mild temperatures which helps promote settlement. Snow changes over time through a process called sublimation.
Sublimation is the change of a solid directly into a gas without first becoming a liquid.
With mild temperatures water vapor travels from the arms of the crystal to refreeze at the center. This produces a rounding of the snowflake. These rounds will often begin to form necks and bond to each other. The process is sometimes called destructive metamorphosis. This will generally produce a good cohesive layer of snow.