omg, apparently the presence of bacteria facilitates snow formation at higher temperatures.
One of the authors of the study, Prof. David Sands, postulates that forming rain or snow is part of the bacterial life cycle; "We think if (the bacteria) couldn't cause ice to form, they couldn't get back down to the ground," Sands said. "As long as it rains, the bacteria grow."
Sands suggests that changing bacterial populations may affect rainfall; for example, overgrazing during a summer could reduce the bacterial population, resulting in lower raindrop formation, although more work would need to be done to firm up this theory. Regardless, it is an interesting glimpse into the world of the snowflake.
This is totally fucked up :D