Look at the pattern water makes when it gives off heat to form crystals.
Now, look at the equally angular patterns its angular crystals (snow) make when they fall on a grassland hill. Flakes might fall evenly from the sky, but they do not distribute themselves evenly on grass.
Grass would appear to be having the same effect on the stilling of water as freezing does on the surface of a stream. Here’s another shot. As you can see, it’s not adhering to itself very well. The angled bonds within the snowflakes are stronger than the ability of angled bits to hold onto each other against gravity.
Gravity is no match for water.