Thundersnow

A 30-foot-radius sphere of whirling snow and wind springs into existence centered on a point you choose within range. The sphere remains for the spell’s duration, and the sphere's space is considered difficult terrain. If a creature enters the sphere's space on its turn or starts its turn there, it must succeed on a Strength saving throw. Huge or larger creatures have advantage on this saving throw. On failure it takes 3d6 bludgeoning and 3d6 cold damage and is dragged 5 feet towards the center of the sphere. On a success, it takes half as much damage and isn't dragged.

When the spell is cast, and as a bonus action on subsequent turns until the spell ends, you can cause thunder to crash within the sphere and a bolt of lightning to leap from the center of the sphere toward one creature you choose within 60 feet of the center. Make a ranged spell attack. You have advantage on the attack roll if the target is in the sphere. On a hit, the target takes 5d6 lightning damage. Additionally, each creature within the sphere must make a constitution saving throw or take 3d6 thunder damage.

Creatures within 40 feet of the sphere have disadvantage on Wisdom (Perception) checks made to listen.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the damage increases for each of its effects by 1d6 for each slot level above 7th.