Your best bet is to log onto the UK met office site, (
www.meto.gov.uk) go to aviation, register and look at the TAFS and METARS. That way you can tell the current and forecast wind and (if you know the runway headings) which runway is most likely to be in use at any airport and most of the smaller fields in the civilised world.
Armed with that HEATHROW DIRECTOR can probably tell you how they alternate lefts and rights on 27 & 09.
DGG