I am an end terrace and regularly get strong winds from  the south west. I had some wooden fascia, soffit and cladding replaced with upvc about five years ago. Over the last six months, strong winds have caused a noisy intermittent, howling sound, keeping us awake at night, outside and just above our bedroom window. When I went outside recently and took a look at the upvc, the gap between the top panels of the cladding  ( either side of 2 windows)  and the next ones down is dirty, whereas all the rest are reasonably clean.  
This makes me think that somehow the wind is finding its way underneath the top panels and causing the noise. I am, of course, just guessing - does any body have any experience of this?