Anyone know what or how Lunar Howl changes your werewolf?

It is possible to get four positive traits instead of the negative ones. I got it on my werewolf. It's basically random, but I did lunar howl up on the "hill" in Moonwood Mill. I tried lunar howl on different locations like the magic HQ, but ends up as random everywhere so that didn't matter.

I guess it could be that the more powerful you are as a werewolf, the more likely you are to get more positive traits when you lunar howl, but I can't confirm that in any way.