For grid points equal to zero, the WPC 48-hour QPF is multiplied by 1/8 (0.125) for each time stamp then written out to the post-processed grid file.
If GEFS_MEAN = 0, then WPC_48-hr x 0.125
For grid points where the ensemble mean QPF is greater than zero, the GEFS 6-hour QPF at that time stamp is divided by the GEFS 48-hour QPF. Then that quotient is multiplied by the WPC 48-hour QPF.
If GEFS_MEAN > 0, then (GEFS_6-hr QPF/GEFS_48-hr QPF) x WPC 48-hour QPF
GIF images are then made from the post processed grid data.
At this time we are currently using the GEFS MEAN, but hope to incorporate ensemble QPF from the CMC MEAN and ECMWF MEAN in the near future.