What about "Shelter from the Storm", the 3rd part of the War of the Burning Sky saga? The stormy weather builds over the course of the adventure and the climax is trying to stop it (and the bad guy behind it). It shouldn't be too hard to adapt to a non-WOTBS setting, and has an Arcana Evolved feel to it. I think the bad guy is a druid, so you could swap him for a Greenbond or Wind Witch without too much problem.
Also, "Dark Clouds Gather" is an old 1st Ed. module that revolves around the efforts to stop a possessed cloud giant. It's quite high level, but having played through it I can confirm that it's good fun.
Goodman did a similar sounding Dungeon Crawl Classic - Assault on Stormbringer Castle, although I don't know the specifics of that. Evil cloud giants again.