Static projectile spells that summon a cloud to rain down liquid below.
This spell creates a roaring cloud above the casting location which rains down water and periodically fires lightning bolts downwards.
Thundercloud creates a powerful crowd control area effect that decimates enemies passing underneath it, especially slower ones, making it ideal for ambushes.
The cloud can be a bit finicky to place correctly. You can either use a spell with timer, or do so in melee range provided that you have immunity to electricity via a perk. A spell with trigger is less desirable since it will only proc on impact, which may block the lightning bolts if a ceiling is struck.