Snows in grains

The snow in grains is a Précipitation which is formed in two manners:

of very small flakes of Snow melting partially while crossing a thin layer of air above zero degree Celsius at the time of their descent, then freezing again while arriving in a layer of negative temperature. The flakes can remain individual or agglomerate with several in their cast iron phase according to the collisions which they carry out and the degree of cast iron which returns them more or less " collants".
of droplets of drizzle in Surfusion in a cloud under the freezing point which end up freezing.

Snow in grains is presented in the form of small granules or white plates (less than 1 mm diameter) which rebound little while falling on a surface. Snow in grain never forms important accumulations and fall from Nuage S Stratiforme S, never in downpours. The code METAR of snow in grains is SG.