def _filter_model(self) -> None:
        """
        Remove model data from time series
        """

        for col_name in self._processed_columns:
            self._data.loc[
                (pd.isna(self._data[f"{col_name}_flag"]))
                | (self._data[f"{col_name}_flag"].str.contains(self._model_flag)),
                col_name,
            ] = pd.NA

        # Drop nan-only rows
        self._data.dropna(how="all", subset=self._processed_columns, inplace=True)

        Remove model data from time series
        
meteostat/interface/timeseries.py