Graupel

Awoke this morning to a light cover of snow which always delights as everything looks clean and tidy, (including the muddy path to the back door.) I knew it was going to snow as per the radio and last night there were the first flakes falling, except they weren't flakes, they were those styrofoam balls of snow. You know the ones, they look more fake than the snow at a grade three Christmas pageant. After a little research, it turns out the styrofoam balls are called Graupel and this type of precipitation occurs when snow crystals encounter supercooled cloud droplets. The droplets aren't doing anything; they aren't frozen, or on their way to being frozen even though it is well past freezing temperature-wise. The cloud droplets only freeze up when they come into contact with something and this would be the snowflakes passing through. Now, the droplets freeze, and they freeze to the surface of the flake in tiny balls until the original shape of the snowflake is no longer recognizable. 

Graupel sample:

 

And something familiar:

This is painted from that terrific book, "Snowflakes" by Ken Libbrecht. It is a great field guide and has perfect photos, of course. The best thing is that he is head-over-heels in love with snow and that really shows through in his writing. So if you want to get enamoured with a flake, this book will do it.