q Collisions between falling
crystals and drops causes
growth through riming and aggregation.
q Riming = liquid water freezing
onto ice crystals
producing rapid
growth.
q Aggregation = the joining
of multiple ice crystals
through the
bonding of surface water
builds ice
crystals to the point of
overcoming
updrafts
q Collision combined with riming and
aggregation allow formation of precipitation within 1/2 hour of
initial formation.