Hey all,
Thank you very much for testing and providing amazing info for this issue. The WoW team has identified the root cause for this FPS behavior and they are looking to push out the fix soon.
In the meantime here is the work around that should clear up the FPS issues in those specific areas.
- Navigate to the WoW directory (In the Battle.net app go to Options → Show in Explorer)
- Open the
_retail_ > WTF > Config.wtf
file in Notepad (or text editor of choice) - Delete the
SET SkyCloudLOD
line completely - Save the file and launch the game from the Battle.net app