Ash-polar vortex

Until the spell ends, ash and snow slowly fall in a 40-foot-tall, 20-foot-radius cylinder centred on a point you choose within range. The area becomes incredibly cold, and exposed flames within it are extinguished.

The ground inside the area is considered difficult terrain. Creatures inside the area take a −1d4 penalty to all saving throws and must succeed on a Constitution saving throw against your spell save DC or take 4d4 cold damage, or half as much damage on a successful save.

When you cast this spell using a spell slot of 4th level or higher, the cold damage increases by 1d4 for each spell level above 3rd.