A storm cloud (10-ft cylinder, 10-ft tall) appears 100 feet above a point within range. For 10 minutes (Concentration), you can use your action to call down a bolt of lightning on a point you can see below the cloud: each creature within 5 feet makes a DEX save or takes 3d10 Lightning (half on success). Outdoors in a storm: +1d10 damage. Higher Slot: +1d10 damage per slot level above 3.