Best way to explain what happens is to just look at this (https://www.dropbox.com/s/18r9xl78ck4y4ov/visualbug.png).
DxDiag (https://www.dropbox.com/s/bo895rngjd0e1in/DxDiag.txt)
I first noticed something similar to this, but not exactly the same, when fog weather occurred for the first time.
With this save, it happens every time I load it up after about 10-20 sec of play or a little faster when I completely zoom out.
Going to try a new game to see if it happens again.
You should upload the save file, as that may help locate the cause of the problem.
Can you double check what version you are running?
It is a known and reported issue.
Thanks for reporting
I have a save with the same bug. I can send you the game file if you want.
please do
It won't allow me to post the file cause it exceeds the max file size, but here is a link to it through Google Drive. https://drive.google.com/file/d/0B8uPxu03-SYMcGhVVkJiQnlqbzg/edit?usp=sharing
Thank you will try it out as soon as my brain allows it