Cazita's Electrical Storms

You summon an enormous storm cloud that bring down a barrage of rapid chaotic lightning and booming thunder in four areas you can see within range. Each creature in a 30ft radius sphere centered on each point you choose must make a dexterity saving throw. A creature takes 10d12 lightning damage and 10d12 thunder damage on a failed save or half as much on a success. A creature in the area of multiple storms is only affected by one. Objects and environments are affected within reason.