Extract the instantaneous GFS forcing fields for MOM6 at f000 from the correct GFS file

[MariaAristizabal-NOAA]

Description

Correct a bug related to the GFS files from which the instantaneous fields used for MOM6 forcing are extracted at f000. Currently for the corresponding forecast cycle, e. g. 2021092712, the instantaneous fields at f000 are extracted from the previous GFS file 2021092706 f006.

Proposed solution

Update the script /ush/hafs_mom6_gfs_forcings.py to read the instantaneous GFS fields at f000 from the corresponding HAFS forecast cycle, e.g. for cycle 2021092712, the instantaneous fields at f000 will be extracted from the GFS cycke 2021092712 f000.

Status

This change will be implemented in the next version of HAFS.