I hope too that summoning an water elemantal on a lake of fire will make a pitiful smoke creature... And on the other hand,summoning a fire elemental on the same pool would make a gorgeous firelavathing very powerful ... (for exemple, if the dungeon is a Volcano, our fire spells should be awesome, but the enemies wouldn't be sensitive to fire ... What a nice ironie ...
But, generating water (rain (which becomes smoke because it's very hot) + rain (this time, it's raining) + rain( What, three characters spanning the same spell ? WTF ? ), the lava may become more "solid", allowing new places to be reached ...
I don't know if this is possible, but stacking weather effect may already be in your mind ...
(I think of Ghostmaster on PC, in which you could raise an hurricane by staking wind ,rain, thunder usw...)
And, imagine what would happen if you design some "very gorgeous" elemental if spawn in an hurricane ...
I know, I'm dreaming, but hey, you maid me !