Avalanche

A bright streak flashes from you to a point you choose within range and then expands into a crushing mass of ice and snow. Each creature in a 20-foot-radius Sphere centered on that point makes a Dexterity saving throw, taking 8d6 Cold damage and imposing the prone condition on a failed save or half as much damage and no prone condition on a successful one.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.