As long as she's not getting focus fired, Nanoha's aerial mobility makes it fairly easy to swerve around the occasional snowball thrown her way (even if she is shivering a bit from Aeneas' assault). In lieu of massive barrages, though, she's settled for single precision strikes - every so often, people down on the ground might find snow forming itself into a little plank and flinging itself at them. But it's from far enough away to give them plenty of time to dodge... usually, anyway.