Drifts of Snow

When you cast this spell, a 30-foot radius sphere of gentle wind and snow begins to fall around the chosen location, and that area becomes rough terrain. Any creature in this sphere takes 3d6 ice damage and an extra 2d6 per turn they spend in the sphere if they end their turn there. A creature that spends 3 consecutive turns in the sphere falls unconscious until awakened or  until one turn after the spell ends. On your turn, you may move the sphere 10 feet.