Hi Estaban, First of all the Java Grib package doesn't write out Grib. But any parameter can have 2 values, like your example about swell1 and swell2. Sample documentation is located at: http://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_temp4-0.shtml 23 Type of first fixed surface (see Code table 4.5) 24 Scale factor of first fixed surface 25-28 Scaled value of first fixed surface 29 Type of second fixed surfaced (see Code table 4.5) 30 Scale factor of second fixed surface 31-34 Scaled value of second fixed surfaces There is a package available to write grib2, it's call wgrib2 RObb... Ticket Details =================== Ticket ID: NTS-432886 Department: Support netCDF Decoders Priority: Normal Status: Open