  The growth of snow crystals is dependent on the temperature and saturation of
the environment. In the case of dendrites, Reiter's local two-dimensional model
provides a realistic approach to the study of dendrite growth. In this paper we
obtain a new geometric rule that incorporates interface control, a basic
mechanism of crystallization that is not taken into account in the original
Reiter's model. By defining two new variables, growth latency and growth
direction, our improved model gives a realistic model not only for dendrite but
also for plate forms.
