Glad someone created this post. I fly a CRJ2 and have noticed many times that when on final approach the wind seems have nothing to do with what the tower reported. I have sometimes been expecting serious windshear or turbulence when looking at my wind vector and comparing it to the tower report, only to find a smooth ride all the way to the ground. It can vary from 30 to 180 degrees from the reported, with wind speeds often similar to the tower reports. I always thought it was just because the FMC needed at least a few unaccelerated seconds to spit out the correct wind. All other times the wind vector seems accurate.
rcl