Any water, seemingly at random, will beome very glitchy in the rain. Ponds, pools, puddles; basically anything that has the ripple texture applied to it. I can temportarily get rid of it when I change the anti-aliasing settings but it will come back soon after. It doesn't happen all the time but it will happen eventually while it's raining. I've tried debugging every mod I have and it doesn't seem to matter what I change it will happen, even after doing a fresh install. But due to the bug's tempermental nature its been hard to check when it is or isn't happening. If anyone has any insight on where this is originating from I would appreciate it, there's a chance it is mod related but I wish I had some understanding of where in the stack of mods this kind of thing could even originate from. Picture below.

GPU anti-aliasing setting doesn't go well with game's edge smoothing mechanis (for me at least).
Did you tried to make a fresh installation on the GPU drivers? When you make an driver installation on it you must tick on the Clean installation checkbox to make an clean installation of the GPU drivers. After the update your in-game settings will be set to default values - change graphics settings to the max values, restart the game, clean the cache files.