aspect of snowfall density is the role of in-cloud vertical motions, The max
growth rate is expected to occur near the level of max upward air motion
within the cloud, where the greatest water vapor is delivery occurs (Auer and
crystals will grow relative to their neighbors within the cloud and begin to
fall, thus removing the smaller particles, if this occurs aggregation leads
to the formation of large snowflakes and relatively low snow density.
crystal falling through a cloud of super cooled water droplets will lead to
rimed crystals and very high snow densities.