I haven't heard anything about thunderstorms. I'm here right now, and the park is fun, but definitely not what you'd expect. 8-9 jibs, and they're working on a jump. They also have more rails and boxes stashed on the side of the fenced in area where the park is now, so i'm expecting that they will build more stuff. This is nothing bad on the park crew, on the contrary, they have done an amazing job at even having anything with the current snow conditions.
Afternoon thunderstorms are pretty likely all week, and could produce some brief but heavy rain. Shouldn't be much of an issue until mid afternoon though, based on the models and forecast discussions I've been looking at. Skiing should get beat before it really comes in most days.
Bring a fly and/or a tarp for your camping but the skiing should be fine.