issue_comments: 509341467

@rabernat , to answer your question, if I open just two files: ds = xr.open_mfdataset(files[:2], preprocess=drop_coords, autoclose=True, parallel=True) the resulting dataset is: <xarray.Dataset> Dimensions: (feature_id: 2729077, reference_time: 1, time: 2) Coordinates: * reference_time (reference_time) datetime64[ns] 2009-01-01 * feature_id (feature_id) int32 101 179 181 ... 1180001803 1180001804 * time (time) datetime64[ns] 2009-01-01 2009-01-01T01:00:00 Data variables: streamflow (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> q_lateral (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> velocity (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> qSfcLatRunoff (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> qBucket (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> qBtmVertRunoff (time, feature_id) float64 dask.array<shape=(2, 2729077), chunksize=(1, 2729077)> Attributes: featureType: timeSeries proj4: +proj=longlat +datum=NAD83 +no_defs model_initialization_time: 2009-01-01_00:00:00 station_dimension: feature_id model_output_valid_time: 2009-01-01_00:00:00 stream_order_output: 1 cdm_datatype: Station esri_pe_string: GEOGCS[GCS_North_American_1983,DATUM[D_North_... Conventions: CF-1.6 model_version: NWM 1.2 dev_OVRTSWCRT: 1 dev_NOAH_TIMESTEP: 3600 dev_channel_only: 0 dev_channelBucket_only: 0 dev: dev_ prefix indicates development/internal me...