...
The ECMWF model (the Integrated Forecast System (IFS)) currently outputs model-level fields in GRIB2 while pressure and surface level outputs are produced in GRIB1. ERA-Interim, a climate reanalysis dataset provided by ECMWF, is produced in the GRIB edition 1 format. The ERA-Interim data is then made available for download in its native GRIB format, and also in a version converted from GRIB to NetCDF. Note that due to limitations of the NetCDF specifications, the NetCDF version contains fewer parameters (variables) and incomplete metadata (information about the data). The NetCDF format is not formally supported by ECMWF.
ECMWF provides and support supports ecCodes, an Application Program Interface accessible from C, FORTRAN and Python programs developed for encoding and decoding GRIB 1 and GRIB 2 files. ecCodes also provides a useful set of command line tools to give quick access to GRIB messages within the files. MetView is a software tool which allows to read, process and visualise GRIB 1 and GRIB 2 formatted data (see Metview documentation).
...