This would be pretty good if you changed around a few small things. You mostly only see rain when there is something bright highlights it, and snow when something dark is behind it, whatever these specks are they're very thin, long and blurry, so I can only assume it's rain, either way, by covering the entire piece in this rain effect, it looks really blurry. if you had a stronger point of light, you could add more details to the branches of the trees (thereby creating bright spots in the painting for you to show the rain). I also think it would look better if the ground was more varied; right now the ground is just a gradient, and the trees aren't really creating cast shadows on it. But if you made the sides of the road dirt or something, you would not only make it look more realistic, you'd also draw the viewer's attention to the center of the painting, at the end of the road (which could look very cool). Like I said, the changes would be very small, but it would really finalize an already good piece