Originally Posted by
Foullacy
You do not cast Thunder 2 or Thunder 3 in your rotation, they cost too much mana. The only time that you cast anything other than Thunder 1 is during Thunderstorm, which you cast Thunder 3.
Rotation-
Fire until mana is low enough to cast Blizzard III and Thunder I without being OOM
(Blizzard III with 3 stacks of astral fire is a 1.5 second cast)
After you cast Thunder I, you should have already received one tick of mana regen, putting you at half mana, cast Fire III after Thunder I which will give you 3 stacks of astral fire, and you will be at full mana.