To Johalak,

Is your team too far apart that they can't aoe heal?

I don't spread them out in a formation. The healer and dps grouped together, followed the tank in, stopped just inside the circle formed by the tornadoes. I then turn the healer around to face away from the boss. This more or less covers the view of most area in the fight zone, if not all. Did not encounter any tempest appearing from the side.

Good luck, and happy hunting in wow.