Well, I think we have to go to the etymology: "natus" from Latin "nasci" to be born. So something natural is created or brought into being by something. In other words, the word "natural" has strong religious connotations. I'd argue that the Universe must necessarily be supernatural, since everything that is created is brought into being by the Universe or something in it, but the Universe itself CANNOT be created by something else-- or the universe and whatever created it are actually joined in a larger context.
So. . . I'm an atheist universal supernaturalist.
So. . . I'm an atheist universal supernaturalist.