When bad weather arrives at altitude, it generally doesn’t rain, it snows. But snow, especially when it’s cold, doesn’t get wet. But it does get cold.
So what you need is not so much clothes that protect you from the damp outside, but clothes that allow perspiration to escape so that your body stays dry and can cope better with the cold.
If it’s raining, it’s because you’re at a lower altitude, closer to a refuge or the bottom of the valley, so being wet from the outside is less important.
Choose brightly coloured clothes to make it easier to find you when needed.
One last tip: Always keep a small pouch at the bottom of your bag to hold a balaclava, a pair of silk gloves, a pair of nylon overslippers, a survival blanket and a spare pair of shoelaces.