A large white cloud appears 60 feet above a point you choose within range. From the cloud, a huge gust of frozen wind, sleet, and snow covers the field of play. The terrain is now difficult terrain. Each creature in a 20-foot wide, 60-foot tall cylinder centered on that point must make a Strength saving throw. On a failed save, the target is frozen (Stunned) for 2 rounds.

After the last target breaks free of their Stun, the field remains difficult terrain as long as concentration is maintained. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the number of turns frozen (Stunned) increases by one for each slot level above 3rd.