[Beta]

The Yellowstone Anomaly is supposedly the astral equivalent of the Yellowstone Supervolcanoe.  That latter is something that if it blew would coat large parts of North America in ash, ejecting probably over 1000km^3 of material. 

I assume that the astral manifestation is very large (many kilometers across, maybe tens of kilometers), equivalent to the area that would erupt on the physical plane.  But there is a physical manifestation too, since it allows physical travel back and forth with the fae courts.  I'm guessing that the physical manifestation is not of equally large area.  Especially since it has been described as wandering around somewhat, and anything that large would be devastating larger areas that have been described.

Any thoughts on how this thing looks/is sized, either in the astral or the physical?

[Wakshaani]

It changes. Sometimes it's the size of a manhole cover, sometimes it covers an entire city. Sometimes it's a pink cloud, sometimes a raging thunderstorm, sometimes just a vague feeling that's otherwise imperceptible.

And, yes, it jumps around. No one's quite sure how or why, and research into it is hampered by the NAN restricting access to Yellowstone to just themselves.

Whatever it is, however, there's Bigtime Mojo in it and a whole lot of people want to know what's up with it.