Ball Lightning

Point your finger at a point you choose within range. Each creature in a 20-foot-radius sphere centered on that point takes 8d6 lightning damage. If only one creature is targeted, apply critical hit damage.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the lightning damage increases by 1d6, the sphere's radius increases by 10 feet, and the spell's range increases by 10 feet, for each slot level above 3rd.