This is what the original tiles look like in my current WIP version:


I thought you might want to use it for reference while removing outlines on yours. I have some other tiles but not all are finished and I'd rather upload them all together (and some are now obsolete if we're changing base tiles). I was being literal when I said I worked on this.
Hare, I'll speak as a level maker, I always hated group rain / snow tiles. I consider them useless. There are two basic ways you can think of putting them in a level:

Awful. It makes completely no sense for snow to fall in groups like that.

Rather bad. It looks repetitive and too much like tiles.

It's a much better solution to put each particle of snow on a separate tile. This way you give level makers more freedom, allow for better eyecandy and even give the tileset better AngelScript support.