I don't know about the BA flight but I was pax in and then back out on CX and the wx was atrocious. Not a pleasant ride, +RA, nasty xwind, mod turbulence and judging by an armful of power at about 100', some nasty sheer as well. Kids loved it, Mrs not so sure. Nice job CX 170.
Was delayed several hours outbound as apron ops were suspended due Cb / lightning. As we taxied out, plenty of standing water, well in excess of 3mm. I understand the airport closed shortly after that and that HKG generally had 12" of rain in 24 hours with extensive flooding downtown.