Personally I don't see the snow mod as weather, at least not if it's the snow mod I'm guessing you're talking about which is the one that pretty much just changes the ground textures to snow lookalike-ish. When I thought of this theme, weather, I was thinking more of some kind of precipitation such as falling snow, rain, wet ground (lynce-style), thunderstorm, lightning, heck, throw a tornado in there if you want to since that's a type of weather as well. Of course, you can combine a few of these weather types if you want to.
Edit: Also, for those of you who are giving up saying "I can't do this".. read through a couple of tutorials, watch some tutorials on youtube for these kind of special effects, etc. When I first started out doing those special effects myself (rain/thunderstorm/lightning strikes etc) I also thought that "I can't do this", but it took me a couple of hours before I started figuring out some good ways to accomplish these things, using the program After Effects. So my advice would be, don't give up that easily. You won't learn anything if you give up so easily, try it out, experiment and mess around with some stuff and I'm sure you can come up with something.