Going snowboarding this weekend and it may rain a bit. I don't have any goretex/completely waterproof gear. All my stuff is just water resistant. My pants are 15k but pretty used so they get wet a bit easier. I have a gore windstopper jacket, which is fine normally snow, but water will eventually get through the seams if it is raining. Debating on picking up a poncho from a military surplus store. Or just straight up wearing a garbage bag over my clothes. Think it will be okay? My biggest concern is water seeping into my ass when I sit on the chairlift, the poncho will cover my ass but concerned about water seeping through it.