whats something fun to do when its snowing hard?

SKI!!!!

It depends on how much snow there is. If the weather is shitty enough, the Valley and some of the main waterfall hikes might be bearable (as opposed to being choked with tourists in buses and RV's). Vernal falls is mellow and rewarding, and the hikes from Glacier Point have amazing views and are often less crowded (Picture below). But if there's a lot of snow, I'd recommend getting some snowshoes or xc skis, which I think you can rent somewhere in the park, and trying to get away from everyone to really appreciate the place. If you talk to the rangers at the backcountry permit stations, they can usually point you in the right direction too.

View Submitted By: Ben. on Apr 11, 2012