Convergence

You become a conduit for static in the air, shocking creatures around you with a discharge of lightning. Each creature within a 20-foot sphere around you must make a Dexterity saving throw. A creature takes 4d6 lightning damage on a failed save, or half as much damage on a successful one. If you are outdoors in stormy conditions when you cast this spell, the spell's damage increases by 2d6.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 2d6 for each slot level above 2nd.