There are a couple of places to check for patch notes and information about upcoming patches.
The first is the “Official News and Announcements” section
This is the latest post in this section re: next patch
The others are the sections entitled “(PC) Updates and bugs” or if you are on a consoles the Xbox or PS4 sections for Updates and Bugs.
They post the latest patch information in each section and move the older patch notes to within a post that has “Archived” in its title such as:
Scroll to the top of the post to find the most recent archived patch notes.
If you want to know what the next round of patches might bring then checking the testlive section of the forums will give hints.