Arin's pocket Blizzard

A frigid globe of cold energy streaks from your fingertips to a point of your choice within range, where it explodes in a 20-foot-radius sphere. Each creature within the area must make a Constitution saving throw. On a failed save, a creature takes 6d6 cold damage. On a successful save, it takes half as much damage. 

The Storm rages on until your next turn if any creature ends its turn inside the space of the blizzard it must make a Constitution saving throw. On a failed save, a creature takes 2d6 cold damage. On a successful save, it takes half as much damage. 

If the globe strikes a body of water or a liquid that is principally water (not including water-based creatures), it freezes the liquid to a depth of 6 inches over an area 30 feet square. This ice lasts for 1 minute. Creatures that were swimming on the surface of frozen water are trapped in the ice. A trapped creature can use an action to make a Strength check against your spell save DC to break free. If the creature succeeded on its saving throw it makes the roll with advantage

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the initial damage increases by 1d6 for each slot level above 3rd.