Today is Wednesday, July 27th. Next weekend is August 6-7.
Now, imagine that it's Monday or Tuesday (July 25th/26th). Next weekend is July 29-31.
If it's Saturday - Tuesday, the next Saturday/Sunday encountered (excepting the weekend you are currently experiencing) is "next weekend". In this scenario, "this coming weekend" can also be used. Don't use "this weekend" if the day on which you are commenting happens to be on a Saturday or Sunday. That's confusing. However, if it's a Monday or a Tuesday, you are free to use "this weekend".
If it's Wednesday - Friday, the next Saturday/Sunday encountered will be "this weekend". "This coming weekend" can also be used. "Next weekend" will be the weekend that follows "this weekend" or "this coming weekend".
Well, that's settled.