Blizzard

Storm clouds form in the sky as a torrential downpour of snow falls from the sky in a location you choose within range. The area of the blizzard forms a 20-foot sphere in a location you choose. This spell must be cast outdoors. Each creature in the 20-foot sphere must make a constitution saving throw. The creatures take 10d6 cold damage on a failed save, and half as much on a successful one. 

Additionally each creature that starts its turn or enters the blizzard must also make a constitution saving throw. Each creature takes 10d6 cold damage on a failed save, and half as much on a successful one.

While creatures are inside of the blizzard, all visibility is reduced to 10 feet and moving through the blizzard is considered difficult terrain.