I realize this is potentially one of those "could be a lot of things" problems, but I figured I'd post up while I'm thinking about it.
Basically, whenever I drive either during or after any decent amount of rain, I notice the car has a lot less power than it usually does. It takes longer to spool up, and kind of feels like the car is fighting against me when I try to make it go. I noticed this last year as well but during the winter it doesn't really rain up here. Still has decent power, turbo still spools up, just not to the extent that it does when it's not raining. No other issues that I've noticed. It idles fine, drives fine, no funny noises when it's wet or dry.
Anybody else have this problem?