Why are snowflakes flat?

(PhysOrg.com) -- We've all heard that no two snowflakes are alike. Caltech professor of physics Kenneth Libbrecht will tell you that this has to do with the ever-changing conditions in the clouds where snow crystals form. read more

Snowflake science: Physicist explains why snowflakes are so thin and flat December 6, 2011 By Kimm Fesenmaier, California Institute of Technology Snow crystals appear in an endless variety of beautiful shapes. read more

Eventually it gets large enough that charge no longer can direct all water hitting the snowflake, but by then the flake is not spherical and has a distinct flat hexagon shape budding, leaving the points more exposed to the cold air. read more

So, snowflakes has to be small amount of matter freezing because when a lot freeze its hailing. As you can see in picture, when water molecules freeze, they create a hexagonal shape because hydrogen is connecting to oxygen of another molecule. read more