Yeah, I was standing as far as possible. I was checking to see multiple spell effects in the air at the same time and I did, and tried to look for MSBT (not too accurate, I'm afraid) that the damage was hitting at when the spell was landing and it seemed to be true as well.
I don't know if this is a recent thing or tied to certain spells or not, but in my guilds Ragnaros video, there are 2 or even 3 wraths in the air simultaneously.