Giant Snowball

You conjure up a massive snowball and send it rolling towards a point within range, where it shatters into a snowy hail of icicles. All creatures in a 5-foot wide line towards the point and within a 10-foot radius sphere of that point must make a Dexterity saving throw. On a failure they take 21 (6d6) cold damage and are knocked Prone. On a success, they take half damage and are not knocked prone.

At higher levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.