A 20-foot-radius sphere of whirling air springs into existence centered on a point you choose within range. The sphere remains for the spell's duration and its space is difficult terrain. Any creature that enters the sphere for the first time on a turn or ends its turn there must make a Strength saving throw or take 1d12 bludgeoning damage.

Until the spell ends, you can use a bonus action on each of your turns to cause a bolt of lightning to leap from the center of the sphere toward one creature you choose within 60 feet of the center. The target must make a Dexterity saving throw. On a failed saving throw, the target takes 3d12 lightning damage. A creature inside the sphere has disadvantage on this saving throw. Further, creatures within 30 feet of the sphere have disadvantage on Wisdom (Perception) checks to hear.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the damage increases for each of its effects by 1d12 for each two slot levels above 4th. If the spell is cast with a 9th level spell, you can instead have the sphere centered on you for the duration, affecting only other creatures. If you do so, you also gain a fly speed of 60 feet for the duration.