[Balimon]

The OP is asking what the highest DPS is that these classes can put out, and even if rain spells resist they are added DPS because you can cast other spells while the waves land. For mage I'd say something like this:

Sirocco: 3 waves 1890 / 2 waves 1260 = 171 / 114 dps
Scars of Sigil: 450 damage over 2 seconds = 225 dps
Pet: Let's go with 70 as a good average
Total : 466 dps / 409 dps

Obviously this isn't always doable, and raiding this wouldn't work because of resist rates. But for group / solo content this is doable. I use the Sirocco/SoS combo to kill the shardwurm matriarch in GD, it's the only way for mages to drop it 40% -> 0% in 10 seconds while it's chealing.