120 ft (60 ft cylinder*)
Up to 10 minutes
A storm cloud appears in the shape of a cylinder that is 10' tall with a 60' radius, centered on a point you can see within range directly above you. The spell fails if you can't see a point in the air where the storm cloud could appear (for example, if you are in a room that can't accommodate the cloud).
When you cast the spell, choose a point you can see under the cloud. A bolt of lightning flashes down from the cloud to that point. Each creature within 5' of that point must make a Dex saving throw. If they fail, they take 3d10 lightning dmg; if they succeed, they take half dmg. Until the spell ends, each turn you can use an action to call down lightning again.
If you are outdoors in stormy conditions, the spell gives you control over the existing storm instead of creating a new one, and the spell's dmg increases by 1d10.
When you cast this spell using a spell slot of 4th or higher level, the damage increases by 1d10 for each slot level above 3rd.
Voca Fulmen Oppugno
Verbal Component (Alternative):
I summon forth a storm so frightening, calling down tendrils of lightning.