Brussels Airlines
Currently showing 4 daily in the week during summer 2015 down from 5. Not a lot of seats lost from 11 May as all flights are showing from then, as the RJ100, which is an extra 17 seats per flight over the Dash.
KLM is still showing ll mainline this coming summer except at the weekend and high-summer and is also back to five daily - another increase.
Lufthansa still showing the A321 daily on LH956.
MANFOD
Sunday was remarkable with very low visibility all around the West Midlands but BHX actually received diversions from Luton, Oxford and Coventry!
I do remember the days when the iRVR readers were new and the vis appeared to be 10K yet the RVR was 150m, as Darkbarly has explained away below. More recently it seems the other way around where BHX's RVR's don't spend much time below 200.
Pete