Blizzard

You rain massive shards of ice from the sky over a huge area on a point within range, the resulting impact creates a frozen fog over the battlefield. Each creature in a 60-foot-radius Sphere centered on that point must make a Dexterity saving throw. On a failed save, a creature takes 6d6 Cold damage and 6d6 Slashing damage. On a successful save, it takes half as much damage only. 

The same 60-foot-radius Sphere area is filled with a frozen fog which last for 1 minute. The Sphere is Heavily Obscured. It lasts for the duration or until a strong wind (such as one created by Gust of Wind) disperses it. Any creature that starts its turn within the frozen fog must make a Constitution saving throw. A creature takes 2d10 Cold damage on a failed save or takes half as much on a successful one.

Using a Higher-Level Spell Slot. The damage increases by 4d6 for both Cold damage and Slashing damage for each spell slot level above 8.

(Original homebrew by Inspired Arcana)