Step-by-step guide
Try using grib_open_file (Fortran interface) with mode "a" instead of "w".
The "a" mode means: Append to a file. Writing operations append data at the end of the file. The file is created if it does not exist.
Try using grib_open_file (Fortran interface) with mode "a" instead of "w".
The "a" mode means: Append to a file. Writing operations append data at the end of the file. The file is created if it does not exist.