High Quality Content by WIKIPEDIA articles! QFF is a Q code. It is the MSL pressure derived from the barometric pressure at the station location by calculating the weight of an imaginary air column, extending from the location to sea level, assuming the temperature and relative humidity at the location are the long term monthly mean, the temperature lapse rate is according to ISA and the relative humidity lapse rate is zero. QFF also stands for Quo Fata Ferunt (a Dutch conspiracy website).