Supernatural is "above" paranormal because anything supernatural is presumed to deal with things above our reality (e.g., God, angels, etc). Science can't explain something supernatural because science is "natural."
Paranormal relates to things that can't be explained by science (e.g. mind reading) but don't necessarily come from supernatural sources "above." The "para-" part of the word is comes from the Greek meaning "beside" so the word can be understood to literally mean "beside normal."