Call Avalanche

A wave of snow springs into existence at a point you choose within range. You can make the wave up to 300 feet long, 300 feet high, and 50 feet thick. The wave lasts for the duration.
     When the wave appears, each creature within its area must make a Strength saving throw. On a failed save, a creature takes 10d4 bludgeoning damage and 10d4 cold damage, or half as much damage on a successful save.
     At the start of each of your turns after the wave appears, the wave, along with any Huge or smaller creatures in it, moves 50 feet in a direction you choose. Any creature inside the wave or whose space   the wave enters when it moves must succeed on a Strength saving throw or take 9d4 bludgeoning damage and 9d4 cold damage. A creature can take this damage only once per round. Additionally, any exposed flames that the avalanche moves over, including those created by spells of 8th level or lower, are extinguished. At the end of the turn, the wave’s height is reduced by 30 feet, and the damage creatures take from the spell on subsequent rounds is reduced by 1d4 for both damage types. When the wave reaches 0 feet in height, the spell ends.
     Any Huge or smaller creature caught in the avalanche is prone and restrained for the duration of the spell.