Volcanic Storm

Chunks of hot volcanic rock and clumps of ash pound down when this spell is cast. All creatures in the area must make a Dexterity saving throw, taking 3d8 points of bludgeoning damage and 5d6 points of fire damage, half on a success. This damage occurs every turn at the start of your turn for the remaining duration of the spell. Heavy ash rains down in the area, imposing disadvantage on Perception skill checks and the entire area is treated as difficult terrain. At the end of the duration, the rock and ash disappear, leaving no aftereffects (other than the damage dealt).