python-xarraygribnoaapygrib

Convert grib2 files to csv

I am working on a classification problem with grib2 files. I have been trying Xarray, pynio, pygrib to read these data but couldn't solve it yet. Can anybody explain what is the structure of grib2 files? How they are created? Is there any quick way to convert them into csv?

Solution

    1. I would recommend to use cfgrib. It is the state of the art python tool using eccodes. It is fully integrated into xarray.

    2. When you open a grib file there are two ways you should know: The first one requires (if several variables in the file) a filter argument:

    import xarray

grib_data = xarray.open_dataset('/path/to/your/grib_file.grb', engine='cfgrib', backend_kwargs={'filter_by_keys':{'typeOfLevel': 'heightAboveGround','level': 2}})

    To get all variables from the file you can use cfgrib's open_datasets:

    import cfgrib
grib_data = cfgrib.open_datasets('/path/to/your/grib_file.grb')

    grib_data will be a list of xarray.Dataset.

    1. If you are receiving default parameter names like paramId0 it is likely that you need the right grib tables. These are provided by the weather service who published the grib file and should be placed at ECCODES_DEFINTION_PATH