id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
286072335,MDU6SXNzdWUyODYwNzIzMzU=,1809,WRF output : cannot serialize variable,5695215,closed,0,,,11,2018-01-04T18:23:44Z,2023-09-25T11:30:35Z,2023-09-25T11:30:35Z,NONE,,,,"#### Code Sample, a copy-pastable example if possible

```python
md.to_netcdf('modified_wrf_input.nc')

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-55-ccba003701f9> in <module>()
----> 1 md.to_netcdf('modified_wrf_input.nc')

/Users/gbromley/anaconda/lib/python3.5/site-packages/xarray/core/dataset.py in to_netcdf(self, path, mode, format, group, engine, encoding, unlimited_dims)
    981         return to_netcdf(self, path, mode, format=format, group=group,
    982                          engine=engine, encoding=encoding,
--> 983                          unlimited_dims=unlimited_dims)
    984 
    985     def __unicode__(self):

/Users/gbromley/anaconda/lib/python3.5/site-packages/xarray/backends/api.py in to_netcdf(dataset, path_or_file, mode, format, group, engine, writer, encoding, unlimited_dims)
    581     try:
    582         dataset.dump_to_store(store, sync=sync, encoding=encoding,
--> 583                               unlimited_dims=unlimited_dims)
    584         if path_or_file is None:
    585             return target.getvalue()

/Users/gbromley/anaconda/lib/python3.5/site-packages/xarray/core/dataset.py in dump_to_store(self, store, encoder, sync, encoding, unlimited_dims)
    907         if encoding is None:
    908             encoding = {}
--> 909         variables, attrs = conventions.encode_dataset_coordinates(self)
    910 
    911         check_encoding = set()

/Users/gbromley/anaconda/lib/python3.5/site-packages/xarray/conventions.py in encode_dataset_coordinates(dataset)
   1052     non_dim_coord_names = set(dataset.coords) - set(dataset.dims)
   1053     return _encode_coordinates(dataset._variables, dataset.attrs,
-> 1054                                non_dim_coord_names=non_dim_coord_names)
   1055 
   1056 

/Users/gbromley/anaconda/lib/python3.5/site-packages/xarray/conventions.py in _encode_coordinates(variables, attributes, non_dim_coord_names)
   1015             raise ValueError('cannot serialize coordinates because variable '
   1016                              ""%s already has an attribute 'coordinates'""
-> 1017                              % var_name)
   1018         attrs['coordinates'] = ' '.join(map(str, coord_names))
   1019 

ValueError: cannot serialize coordinates because variable FSA already has an attribute 'coordinates'

```
#### Problem description

This dataset is the wrfinput_d01 file for use with the WRF model. Reading and modifying the variables worked, but I cannot figure out how to write the changes out to the file. I get the above error. I saw another post about the same issue, but wasn't sure how it was resolved.


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