OK, it’s actually impossible to guarantee powder on a ski trip you’ve booked well in advance. The only way to do that is to keep one eye on the short-term weather forecasts and purchase a last-minute ticket to wherever is going to get hit next. But even then, there are variables. Will the resort open good terrain? Will your flight be canceled due to the storm? Will the storm bring inches rather than the reported feet? Don’t fret. There are a few trusted places where the perfect powder day lines up more often than not.