Talk:Volume 5 Weiss Character Short/@comment-30530552-20170717204532/@comment-25936766-20170718141320

Technically speaking, snow is nothing more than a bunch of diminute ice crystals. Snow is to ice what sand is to rocks.

So I'm perfectly sure it was just Ice Dust. More exactly, Winter manipulating the Ice/Snow in that Mini-Blizzard she made, either directly or via Glyphs.