Acid Rain

You unleash a storm of swirling acid in a cylinder 20ft. wide and 30ft. high centered on a point that you can see. The area is heavily obscured by driving acid fall. A creature that starts its turn or enters the area for the first time must succeed a DEX save taking 6d6 acid damage on a failure or half damage on a success. A creature that fails the save takes 3d6 acid damage at the end of its next turn. 

On each of your turns after you cast this spell, you can use an action to move the storm up to 60 feet in any direction.

At Higher Levels: add 1d6 for each spell slot level above 5th.