Conjure Blizzard

You cut a rift into a snowy dimension (or some other blizzard location), conjuring a 50ft long 10ft wide line of cold air. Any creature in the effected area makes a constitution saving throw. On a failed save a creature takes 6d6 cold damage or half as much on a successful save. Creatures who fail there save must make an Arcana or Sleight of Hand check equal to your spell save DC to be able to cast any spell with somatic components until the end of their next turn.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3rd.