Contents

Overview
Prerequisites
Imports
Access real-time NWP data from Unidata’s THREDDS server
Use Xarray’s plot.imshow to display gridded data as an image
Use Xarray’s open_rasterio method to open high-resolution elevation data
- Examine these Datasets
Close the file handles so they don’t stay resident in memory.
Summary
- What’s Next?
Resources and References

Rasters 1: Intro to raster data

Overview
Prerequisites
Imports
Access real-time NWP data from Unidata’s THREDDS server
Use Xarray’s plot.imshow to display gridded data as an image
Use Xarray’s open_rasterio method to open high-resolution elevation data
- Examine these Datasets
Close the file handles so they don’t stay resident in memory.
Summary
- What’s Next?
Resources and References

Rasters 1: Intro to raster data¶

Overview¶

Access real-time NWP data from Unidata’s THREDDS server
Use Xarray’s plot.imshow to display gridded data as an image
Use Xarray’s open_rasterio method to open and view high-resolution elevation data
Close data objects when you are no longer using them.

Prerequisites¶

Concepts	Importance	Notes
Xarray	Necessary

Time to learn: 15 minutes

Imports¶

import xarray as xr
from datetime import datetime, timedelta

Access real-time NWP data from Unidata’s THREDDS server¶

Parse the current time and choose a recent hour when we might expect the model run to be complete. There is normally a ~90 minute lag, but we’ll give it a bit more than that.

now = datetime.now()
year = now.year
month = now.month
day = now.day
hour = now.hour
minute = now.minute
print (year, month, day, hour,minute)

2023 1 19 17 32

# The previous hour's data is typically available shortly after the half-hour, but give it a little extra time 
if (minute < 45): 
    hrDelta = 3
else:
    hrDelta = 2
runTime = now - timedelta(hours=hrDelta)
runTimeStr = runTime.strftime('%Y%m%d %H00 UTC')
modelDate = runTime.strftime('%Y%m%d')
modelHour = runTime.strftime('%H')
modelDay = runTime.strftime('%D')
print (modelDay)
print (modelHour)
print (runTimeStr)

01/19/23
14
20230119 1400 UTC

Create an object pointing to the dataset.

data_url = 'https://thredds.ucar.edu/thredds/dodsC/grib/NCEP/HRRR/CONUS_2p5km/HRRR_CONUS_2p5km_'+ modelDate + '_' + modelHour + '00.grib2'
data_url

'https://thredds.ucar.edu/thredds/dodsC/grib/NCEP/HRRR/CONUS_2p5km/HRRR_CONUS_2p5km_20230119_1400.grib2'

ds = xr.open_dataset(data_url)
xrdSize = ds.nbytes / 1e9
print ("Size of dataset = %.3f GB" % xrdSize)

Size of dataset = 18.159 GB

ds

<xarray.Dataset>
Dimensions:                                                                                                              (
                                                                                                                          x: 2145,
                                                                                                                          y: 1377,
                                                                                                                          time: 19,
                                                                                                                          time1: 19,
                                                                                                                          time2: 18,
                                                                                                                          ...
                                                                                                                          height_above_ground_layer2_bounds_1: 2,
                                                                                                                          pressure_difference_layer2_bounds_1: 2,
                                                                                                                          height_above_ground_layer3_bounds_1: 2,
                                                                                                                          isobaric_layer_bounds_1: 2,
                                                                                                                          sigma_layer_bounds_1: 2,
                                                                                                                          pressure_difference_layer3_bounds_1: 2)
Coordinates: (12/22)
  * x                                                                                                                    (x) float32 ...
  * y                                                                                                                    (y) float32 ...
    reftime                                                                                                              datetime64[ns] ...
  * time                                                                                                                 (time) datetime64[ns] ...
  * time1                                                                                                                (time1) datetime64[ns] ...
  * time2                                                                                                                (time2) datetime64[ns] ...
    ...                                                                                                                   ...
  * height_above_ground3                                                                                                 (height_above_ground3) float32 ...
  * isobaric_layer                                                                                                       (isobaric_layer) float32 ...
  * sigma_layer                                                                                                          (sigma_layer) float32 ...
  * pressure_difference_layer3                                                                                           (pressure_difference_layer3) float32 ...
  * isobaric                                                                                                             (isobaric) float32 ...
  * isobaric1                                                                                                            (isobaric1) float32 ...
Dimensions without coordinates: time1_bounds_1, time2_bounds_1,
                                pressure_difference_layer_bounds_1,
                                pressure_difference_layer1_bounds_1,
                                height_above_ground_layer_bounds_1,
                                height_above_ground_layer1_bounds_1,
                                height_above_ground_layer2_bounds_1,
                                pressure_difference_layer2_bounds_1,
                                height_above_ground_layer3_bounds_1,
                                isobaric_layer_bounds_1, sigma_layer_bounds_1,
                                pressure_difference_layer3_bounds_1
Data variables: (12/68)
    LambertConformal_Projection                                                                                          int32 ...
    time1_bounds                                                                                                         (time1, time1_bounds_1) datetime64[ns] ...
    time2_bounds                                                                                                         (time2, time2_bounds_1) datetime64[ns] ...
    pressure_difference_layer_bounds                                                                                     (pressure_difference_layer, pressure_difference_layer_bounds_1) float32 ...
    pressure_difference_layer1_bounds                                                                                    (pressure_difference_layer1, pressure_difference_layer1_bounds_1) float32 ...
    height_above_ground_layer_bounds                                                                                     (height_above_ground_layer, height_above_ground_layer_bounds_1) float32 ...
    ...                                                                                                                   ...
    u-component_of_wind_isobaric                                                                                         (time, isobaric1, y, x) float32 ...
    u-component_of_wind_height_above_ground                                                                              (time, height_above_ground2, y, x) float32 ...
    u-component_storm_motion_height_above_ground_layer                                                                   (time, height_above_ground_layer1, y, x) float32 ...
    v-component_of_wind_isobaric                                                                                         (time, isobaric1, y, x) float32 ...
    v-component_of_wind_height_above_ground                                                                              (time, height_above_ground2, y, x) float32 ...
    v-component_storm_motion_height_above_ground_layer                                                                   (time, height_above_ground_layer1, y, x) float32 ...
Attributes:
    Originating_or_generating_Center:                                        ...
    Originating_or_generating_Subcenter:                                     ...
    GRIB_table_version:                                                      ...
    Type_of_generating_process:                                              ...
    Analysis_or_forecast_generating_process_identifier_defined_by_originating...
    file_format:                                                             ...
    Conventions:                                                             ...
    history:                                                                 ...
    featureType:                                                             ...
    _CoordSysBuilder:                                                        ...
    EXTRA_DIMENSION.reftime:                                                 ...

xarray.Dataset

Dimensions:
- x: 2145
- y: 1377
- time: 19
- time1: 19
- time2: 18
- pressure_difference_layer: 1
- height_above_ground: 1
- pressure_difference_layer1: 1
- height_above_ground1: 1
- height_above_ground_layer: 1
- height_above_ground_layer1: 1
- height_above_ground_layer2: 2
- pressure_difference_layer2: 1
- height_above_ground2: 2
- height_above_ground_layer3: 2
- height_above_ground3: 1
- isobaric_layer: 1
- sigma_layer: 1
- pressure_difference_layer3: 2
- isobaric: 4
- isobaric1: 5
- time1_bounds_1: 2
- time2_bounds_1: 2
- pressure_difference_layer_bounds_1: 2
- pressure_difference_layer1_bounds_1: 2
- height_above_ground_layer_bounds_1: 2
- height_above_ground_layer1_bounds_1: 2
- height_above_ground_layer2_bounds_1: 2
- pressure_difference_layer2_bounds_1: 2
- height_above_ground_layer3_bounds_1: 2
- isobaric_layer_bounds_1: 2
- sigma_layer_bounds_1: 2
- pressure_difference_layer3_bounds_1: 2
Coordinates: (22)
- x
  (x)
  float32
  -2.763e+03 -2.761e+03 ... 2.682e+03
  standard_name :
  projection_x_coordinate
  units :
  km
  _CoordinateAxisType :
  GeoX
```
array([-2763.217 , -2760.6772, -2758.1377, ...,  2676.8267,  2679.3662,
        2681.906 ], dtype=float32)
```
- y
  (y)
  float32
  -263.8 -261.3 ... 3.231e+03
  standard_name :
  projection_y_coordinate
  units :
  km
  _CoordinateAxisType :
  GeoY
```
array([-263.79062, -261.25092, -258.7112 , ..., 3225.7612 , 3228.3008 ,
       3230.8406 ], dtype=float32)
```
- reftime
  ()
  datetime64[ns]
  ...
  standard_name :
  forecast_reference_time
  long_name :
  GRIB reference time
  _CoordinateAxisType :
  RunTime
```
array('2023-01-19T14:00:00.000000000', dtype='datetime64[ns]')
```
- time
  (time)
  datetime64[ns]
  2023-01-19T14:00:00 ... 2023-01-...
  standard_name :
  time
  long_name :
  GRIB forecast or observation time
  _CoordinateAxisType :
  Time
```
array(['2023-01-19T14:00:00.000000000', '2023-01-19T15:00:00.000000000',
       '2023-01-19T16:00:00.000000000', '2023-01-19T17:00:00.000000000',
       '2023-01-19T18:00:00.000000000', '2023-01-19T19:00:00.000000000',
       '2023-01-19T20:00:00.000000000', '2023-01-19T21:00:00.000000000',
       '2023-01-19T22:00:00.000000000', '2023-01-19T23:00:00.000000000',
       '2023-01-20T00:00:00.000000000', '2023-01-20T01:00:00.000000000',
       '2023-01-20T02:00:00.000000000', '2023-01-20T03:00:00.000000000',
       '2023-01-20T04:00:00.000000000', '2023-01-20T05:00:00.000000000',
       '2023-01-20T06:00:00.000000000', '2023-01-20T07:00:00.000000000',
       '2023-01-20T08:00:00.000000000'], dtype='datetime64[ns]')
```
- time1
  (time1)
  datetime64[ns]
  2023-01-19T14:00:00 ... 2023-01-...
  standard_name :
  time
  long_name :
  GRIB forecast or observation time
  bounds :
  time1_bounds
  _CoordinateAxisType :
  Time
```
array(['2023-01-19T14:00:00.000000000', '2023-01-19T15:00:00.000000000',
       '2023-01-19T16:00:00.000000000', '2023-01-19T17:00:00.000000000',
       '2023-01-19T18:00:00.000000000', '2023-01-19T19:00:00.000000000',
       '2023-01-19T20:00:00.000000000', '2023-01-19T21:00:00.000000000',
       '2023-01-19T22:00:00.000000000', '2023-01-19T23:00:00.000000000',
       '2023-01-20T00:00:00.000000000', '2023-01-20T01:00:00.000000000',
       '2023-01-20T02:00:00.000000000', '2023-01-20T03:00:00.000000000',
       '2023-01-20T04:00:00.000000000', '2023-01-20T05:00:00.000000000',
       '2023-01-20T06:00:00.000000000', '2023-01-20T07:00:00.000000000',
       '2023-01-20T08:00:00.000000000'], dtype='datetime64[ns]')
```
- time2
  (time2)
  datetime64[ns]
  2023-01-19T15:00:00 ... 2023-01-...
  standard_name :
  time
  long_name :
  GRIB forecast or observation time
  bounds :
  time2_bounds
  _CoordinateAxisType :
  Time
```
array(['2023-01-19T15:00:00.000000000', '2023-01-19T16:00:00.000000000',
       '2023-01-19T17:00:00.000000000', '2023-01-19T18:00:00.000000000',
       '2023-01-19T19:00:00.000000000', '2023-01-19T20:00:00.000000000',
       '2023-01-19T21:00:00.000000000', '2023-01-19T22:00:00.000000000',
       '2023-01-19T23:00:00.000000000', '2023-01-20T00:00:00.000000000',
       '2023-01-20T01:00:00.000000000', '2023-01-20T02:00:00.000000000',
       '2023-01-20T03:00:00.000000000', '2023-01-20T04:00:00.000000000',
       '2023-01-20T05:00:00.000000000', '2023-01-20T06:00:00.000000000',
       '2023-01-20T07:00:00.000000000', '2023-01-20T08:00:00.000000000'],
      dtype='datetime64[ns]')
```
- pressure_difference_layer
  (pressure_difference_layer)
  float32
  1.275e+04
  units :
  Pa
  long_name :
  Level at specified pressure difference from ground to level
  positive :
  up
  Grib_level_type :
  108
  datum :
  ground
  bounds :
  pressure_difference_layer_bounds
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  up
```
array([12750.], dtype=float32)
```
- height_above_ground
  (height_above_ground)
  float32
  10.0
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([10.], dtype=float32)
```
- pressure_difference_layer1
  (pressure_difference_layer1)
  float32
  9e+03
  units :
  Pa
  long_name :
  Level at specified pressure difference from ground to level
  positive :
  up
  Grib_level_type :
  108
  datum :
  ground
  bounds :
  pressure_difference_layer1_bounds
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  up
```
array([9000.], dtype=float32)
```
- height_above_ground1
  (height_above_ground1)
  float32
  1e+03
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([1000.], dtype=float32)
```
- height_above_ground_layer
  (height_above_ground_layer)
  float32
  3.5e+03
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  bounds :
  height_above_ground_layer_bounds
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([3500.], dtype=float32)
```
- height_above_ground_layer1
  (height_above_ground_layer1)
  float32
  3e+03
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  bounds :
  height_above_ground_layer1_bounds
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([3000.], dtype=float32)
```
- height_above_ground_layer2
  (height_above_ground_layer2)
  float32
  500.0 1.5e+03
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  bounds :
  height_above_ground_layer2_bounds
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([ 500., 1500.], dtype=float32)
```
- pressure_difference_layer2
  (pressure_difference_layer2)
  float32
  5.5e+04
  units :
  Pa
  long_name :
  Level at specified pressure difference from ground to level
  positive :
  up
  Grib_level_type :
  108
  datum :
  ground
  bounds :
  pressure_difference_layer2_bounds
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  up
```
array([55000.], dtype=float32)
```
- height_above_ground2
  (height_above_ground2)
  float32
  10.0 80.0
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([10., 80.], dtype=float32)
```
- height_above_ground_layer3
  (height_above_ground_layer3)
  float32
  500.0 3e+03
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  bounds :
  height_above_ground_layer3_bounds
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([ 500., 3000.], dtype=float32)
```
- height_above_ground3
  (height_above_ground3)
  float32
  2.0
  units :
  m
  long_name :
  Specified height level above ground
  positive :
  up
  Grib_level_type :
  103
  datum :
  ground
  _CoordinateAxisType :
  Height
  _CoordinateZisPositive :
  up
```
array([2.], dtype=float32)
```
- isobaric_layer
  (isobaric_layer)
  float32
  7.5e+04
  units :
  Pa
  long_name :
  Isobaric surface
  positive :
  down
  Grib_level_type :
  100
  bounds :
  isobaric_layer_bounds
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  down
```
array([75000.], dtype=float32)
```
- sigma_layer
  (sigma_layer)
  float32
  0.65
  units :
  sigma
  long_name :
  Sigma level
  positive :
  down
  Grib_level_type :
  104
  bounds :
  sigma_layer_bounds
  _CoordinateAxisType :
  GeoZ
  _CoordinateZisPositive :
  down
```
array([0.65], dtype=float32)
```
- pressure_difference_layer3
  (pressure_difference_layer3)
  float32
  4.5e+03 1.275e+04
  units :
  Pa
  long_name :
  Level at specified pressure difference from ground to level
  positive :
  up
  Grib_level_type :
  108
  datum :
  ground
  bounds :
  pressure_difference_layer3_bounds
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  up
```
array([ 4500., 12750.], dtype=float32)
```
- isobaric
  (isobaric)
  float32
  5e+04 7e+04 8.5e+04 1e+05
  units :
  Pa
  long_name :
  Isobaric surface
  positive :
  down
  Grib_level_type :
  100
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  down
```
array([ 50000.,  70000.,  85000., 100000.], dtype=float32)
```
- isobaric1
  (isobaric1)
  float32
  5e+04 7e+04 8.5e+04 9.25e+04 1e+05
  units :
  Pa
  long_name :
  Isobaric surface
  positive :
  down
  Grib_level_type :
  100
  _CoordinateAxisType :
  Pressure
  _CoordinateZisPositive :
  down
```
array([ 50000.,  70000.,  85000.,  92500., 100000.], dtype=float32)
```
Data variables: (68)
- LambertConformal_Projection
  ()
  int32
  ...
  grid_mapping_name :
  lambert_conformal_conic
  latitude_of_projection_origin :
  25.0
  longitude_of_central_meridian :
  265.0
  standard_parallel :
  25.0
  earth_radius :
  6371229.0
  _CoordinateTransformType :
  Projection
  _CoordinateAxisTypes :
  GeoX GeoY
```
array(0, dtype=int32)
```
- time1_bounds
  (time1, time1_bounds_1)
  datetime64[ns]
  ...
  long_name :
  bounds for time1
```
array([['2023-01-19T14:00:00.000000000', '2023-01-19T14:00:00.000000000'],
       ['2023-01-19T14:00:00.000000000', '2023-01-19T15:00:00.000000000'],
       ['2023-01-19T15:00:00.000000000', '2023-01-19T16:00:00.000000000'],
       ['2023-01-19T16:00:00.000000000', '2023-01-19T17:00:00.000000000'],
       ['2023-01-19T17:00:00.000000000', '2023-01-19T18:00:00.000000000'],
       ['2023-01-19T18:00:00.000000000', '2023-01-19T19:00:00.000000000'],
       ['2023-01-19T19:00:00.000000000', '2023-01-19T20:00:00.000000000'],
       ['2023-01-19T20:00:00.000000000', '2023-01-19T21:00:00.000000000'],
       ['2023-01-19T21:00:00.000000000', '2023-01-19T22:00:00.000000000'],
       ['2023-01-19T22:00:00.000000000', '2023-01-19T23:00:00.000000000'],
       ['2023-01-19T23:00:00.000000000', '2023-01-20T00:00:00.000000000'],
       ['2023-01-20T00:00:00.000000000', '2023-01-20T01:00:00.000000000'],
       ['2023-01-20T01:00:00.000000000', '2023-01-20T02:00:00.000000000'],
       ['2023-01-20T02:00:00.000000000', '2023-01-20T03:00:00.000000000'],
       ['2023-01-20T03:00:00.000000000', '2023-01-20T04:00:00.000000000'],
       ['2023-01-20T04:00:00.000000000', '2023-01-20T05:00:00.000000000'],
       ['2023-01-20T05:00:00.000000000', '2023-01-20T06:00:00.000000000'],
       ['2023-01-20T06:00:00.000000000', '2023-01-20T07:00:00.000000000'],
       ['2023-01-20T07:00:00.000000000', '2023-01-20T08:00:00.000000000']],
      dtype='datetime64[ns]')
```
- time2_bounds
  (time2, time2_bounds_1)
  datetime64[ns]
  ...
  long_name :
  bounds for time2
```
array([['2023-01-19T14:00:00.000000000', '2023-01-19T15:00:00.000000000'],
       ['2023-01-19T15:00:00.000000000', '2023-01-19T16:00:00.000000000'],
       ['2023-01-19T16:00:00.000000000', '2023-01-19T17:00:00.000000000'],
       ['2023-01-19T17:00:00.000000000', '2023-01-19T18:00:00.000000000'],
       ['2023-01-19T18:00:00.000000000', '2023-01-19T19:00:00.000000000'],
       ['2023-01-19T19:00:00.000000000', '2023-01-19T20:00:00.000000000'],
       ['2023-01-19T20:00:00.000000000', '2023-01-19T21:00:00.000000000'],
       ['2023-01-19T21:00:00.000000000', '2023-01-19T22:00:00.000000000'],
       ['2023-01-19T22:00:00.000000000', '2023-01-19T23:00:00.000000000'],
       ['2023-01-19T23:00:00.000000000', '2023-01-20T00:00:00.000000000'],
       ['2023-01-20T00:00:00.000000000', '2023-01-20T01:00:00.000000000'],
       ['2023-01-20T01:00:00.000000000', '2023-01-20T02:00:00.000000000'],
       ['2023-01-20T02:00:00.000000000', '2023-01-20T03:00:00.000000000'],
       ['2023-01-20T03:00:00.000000000', '2023-01-20T04:00:00.000000000'],
       ['2023-01-20T04:00:00.000000000', '2023-01-20T05:00:00.000000000'],
       ['2023-01-20T05:00:00.000000000', '2023-01-20T06:00:00.000000000'],
       ['2023-01-20T06:00:00.000000000', '2023-01-20T07:00:00.000000000'],
       ['2023-01-20T07:00:00.000000000', '2023-01-20T08:00:00.000000000']],
      dtype='datetime64[ns]')
```
- pressure_difference_layer_bounds
  (pressure_difference_layer, pressure_difference_layer_bounds_1)
  float32
  ...
  units :
  Pa
  long_name :
  bounds for pressure_difference_layer
```
array([[25500.,     0.]], dtype=float32)
```
- pressure_difference_layer1_bounds
  (pressure_difference_layer1, pressure_difference_layer1_bounds_1)
  float32
  ...
  units :
  Pa
  long_name :
  bounds for pressure_difference_layer1
```
array([[18000.,     0.]], dtype=float32)
```
- height_above_ground_layer_bounds
  (height_above_ground_layer, height_above_ground_layer_bounds_1)
  float32
  ...
  units :
  m
  long_name :
  bounds for height_above_ground_layer
```
array([[5000., 2000.]], dtype=float32)
```
- height_above_ground_layer1_bounds
  (height_above_ground_layer1, height_above_ground_layer1_bounds_1)
  float32
  ...
  units :
  m
  long_name :
  bounds for height_above_ground_layer1
```
array([[   0., 6000.]], dtype=float32)
```
- height_above_ground_layer2_bounds
  (height_above_ground_layer2, height_above_ground_layer2_bounds_1)
  float32
  ...
  units :
  m
  long_name :
  bounds for height_above_ground_layer2
```
array([[1000.,    0.],
       [3000.,    0.]], dtype=float32)
```
- pressure_difference_layer2_bounds
  (pressure_difference_layer2, pressure_difference_layer2_bounds_1)
  float32
  ...
  units :
  Pa
  long_name :
  bounds for pressure_difference_layer2
```
array([[ 10000., 100000.]], dtype=float32)
```
- height_above_ground_layer3_bounds
  (height_above_ground_layer3, height_above_ground_layer3_bounds_1)
  float32
  ...
  units :
  m
  long_name :
  bounds for height_above_ground_layer3
```
array([[   0., 1000.],
       [   0., 6000.]], dtype=float32)
```
- isobaric_layer_bounds
  (isobaric_layer, isobaric_layer_bounds_1)
  float32
  ...
  units :
  Pa
  long_name :
  bounds for isobaric_layer
```
array([[ 50000., 100000.]], dtype=float32)
```
- sigma_layer_bounds
  (sigma_layer, sigma_layer_bounds_1)
  float32
  ...
  units :
  sigma
  long_name :
  bounds for sigma_layer
```
array([[0.5, 0.8]], dtype=float32)
```
- pressure_difference_layer3_bounds
  (pressure_difference_layer3, pressure_difference_layer3_bounds_1)
  float32
  ...
  units :
  Pa
  long_name :
  bounds for pressure_difference_layer3
```
array([[ 9000.,     0.],
       [25500.,     0.]], dtype=float32)
```
- Categorical_freezing_rain_surface
  (time, y, x)
  float32
  ...
  long_name :
  Categorical freezing rain @ Ground or water surface
  units :
  (Code table 4.222)
  abbreviation :
  CFRZR
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-34_L1
  Grib2_Parameter :
  [ 0 1 34]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Categorical freezing rain
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Categorical_ice_pellets_surface
  (time, y, x)
  float32
  ...
  long_name :
  Categorical ice pellets @ Ground or water surface
  units :
  (Code table 4.222)
  abbreviation :
  CICEP
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-35_L1
  Grib2_Parameter :
  [ 0 1 35]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Categorical ice pellets
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Categorical_rain_surface
  (time, y, x)
  float32
  ...
  long_name :
  Categorical rain @ Ground or water surface
  units :
  (Code table 4.222)
  abbreviation :
  CRAIN
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-33_L1
  Grib2_Parameter :
  [ 0 1 33]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Categorical rain
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Categorical_snow_surface
  (time, y, x)
  float32
  ...
  long_name :
  Categorical snow @ Ground or water surface
  units :
  (Code table 4.222)
  abbreviation :
  CSNOW
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-36_L1
  Grib2_Parameter :
  [ 0 1 36]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Categorical snow
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Convective_available_potential_energy_pressure_difference_layer
  (time, pressure_difference_layer3, y, x)
  float32
  ...
  long_name :
  Convective available potential energy @ Level at specified pressure difference from ground to level layer
  units :
  J/kg
  abbreviation :
  CAPE
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-6_L108_layer
  Grib2_Parameter :
  [0 7 6]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Convective available potential energy
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- Convective_available_potential_energy_surface
  (time, y, x)
  float32
  ...
  long_name :
  Convective available potential energy @ Ground or water surface
  units :
  J/kg
  abbreviation :
  CAPE
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-6_L1
  Grib2_Parameter :
  [0 7 6]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Convective available potential energy
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Convective_inhibition_pressure_difference_layer
  (time, pressure_difference_layer3, y, x)
  float32
  ...
  long_name :
  Convective inhibition @ Level at specified pressure difference from ground to level layer
  units :
  J/kg
  abbreviation :
  CIN
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-7_L108_layer
  Grib2_Parameter :
  [0 7 7]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Convective inhibition
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- Convective_inhibition_surface
  (time, y, x)
  float32
  ...
  long_name :
  Convective inhibition @ Ground or water surface
  units :
  J/kg
  abbreviation :
  CIN
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-7_L1
  Grib2_Parameter :
  [0 7 7]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Convective inhibition
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Dewpoint_temperature_isobaric
  (time, isobaric1, y, x)
  float32
  ...
  long_name :
  Dewpoint temperature @ Isobaric surface
  units :
  K
  abbreviation :
  DPT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-0-6_L100
  Grib2_Parameter :
  [0 0 6]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Temperature
  Grib2_Parameter_Name :
  Dewpoint temperature
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[280598175 values with dtype=float32]
```
- Dewpoint_temperature_height_above_ground
  (time, height_above_ground3, y, x)
  float32
  ...
  long_name :
  Dewpoint temperature @ Specified height level above ground
  units :
  K
  abbreviation :
  DPT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-0-6_L103
  Grib2_Parameter :
  [0 0 6]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Temperature
  Grib2_Parameter_Name :
  Dewpoint temperature
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Echo_top_cloud_tops
  (time, y, x)
  float32
  ...
  long_name :
  Echo top @ Level of cloud tops
  units :
  m
  abbreviation :
  RETOP
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-16-3_L3
  Grib2_Parameter :
  [ 0 16 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Forecast Radar Imagery
  Grib2_Parameter_Name :
  Echo top
  Grib2_Level_Type :
  3
  Grib2_Level_Desc :
  Level of cloud tops
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Geopotential_height_isobaric
  (time, isobaric, y, x)
  float32
  ...
  long_name :
  Geopotential height @ Isobaric surface
  units :
  gpm
  abbreviation :
  HGT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-5_L100
  Grib2_Parameter :
  [0 3 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Geopotential height
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[224478540 values with dtype=float32]
```
- Geopotential_height_adiabatic_condensation_lifted
  (time, y, x)
  float32
  ...
  long_name :
  Geopotential height @ Level of adiabatic condensation lifted from the surface
  units :
  gpm
  abbreviation :
  HGT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-5_L5
  Grib2_Parameter :
  [0 3 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Geopotential height
  Grib2_Level_Type :
  5
  Grib2_Level_Desc :
  Level of adiabatic condensation lifted from the surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Geopotential_height_cloud_ceiling
  (time, y, x)
  float32
  ...
  long_name :
  Geopotential height @ Cloud ceiling
  units :
  gpm
  abbreviation :
  HGT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-5_L215
  Grib2_Parameter :
  [0 3 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Geopotential height
  Grib2_Level_Type :
  215
  Grib2_Level_Desc :
  Cloud ceiling
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Geopotential_height_surface
  (time, y, x)
  float32
  ...
  long_name :
  Geopotential height @ Ground or water surface
  units :
  gpm
  abbreviation :
  HGT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-5_L1
  Grib2_Parameter :
  [0 3 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Geopotential height
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Geopotential_height_cloud_tops
  (time, y, x)
  float32
  ...
  long_name :
  Geopotential height @ Level of cloud tops
  units :
  gpm
  abbreviation :
  HGT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-5_L3
  Grib2_Parameter :
  [0 3 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Geopotential height
  Grib2_Level_Type :
  3
  Grib2_Level_Desc :
  Level of cloud tops
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- High_cloud_cover_high_cloud
  (time, y, x)
  float32
  ...
  long_name :
  High cloud cover @ High cloud layer
  units :
  %
  abbreviation :
  HCDC
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-6-5_L234
  Grib2_Parameter :
  [0 6 5]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Cloud
  Grib2_Parameter_Name :
  High cloud cover
  Grib2_Level_Type :
  234
  Grib2_Level_Desc :
  High cloud layer
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Low_cloud_cover_low_cloud
  (time, y, x)
  float32
  ...
  long_name :
  Low cloud cover @ Low cloud layer
  units :
  %
  abbreviation :
  LCDC
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-6-3_L214
  Grib2_Parameter :
  [0 6 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Cloud
  Grib2_Parameter_Name :
  Low cloud cover
  Grib2_Level_Type :
  214
  Grib2_Level_Desc :
  Low cloud layer
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Medium_cloud_cover_middle_cloud
  (time, y, x)
  float32
  ...
  long_name :
  Medium cloud cover @ Middle cloud layer
  units :
  %
  abbreviation :
  MCDC
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-6-4_L224
  Grib2_Parameter :
  [0 6 4]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Cloud
  Grib2_Parameter_Name :
  Medium cloud cover
  Grib2_Level_Type :
  224
  Grib2_Level_Desc :
  Middle cloud layer
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Per_cent_frozen_precipitation_surface
  (time, y, x)
  float32
  ...
  long_name :
  Per cent frozen precipitation @ Ground or water surface
  units :
  %
  abbreviation :
  CPOFP
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-39_L1
  Grib2_Parameter :
  [ 0 1 39]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Per cent frozen precipitation
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Planetary_boundary_layer_height_surface
  (time, y, x)
  float32
  ...
  long_name :
  Planetary boundary layer height @ Ground or water surface
  units :
  m
  abbreviation :
  HPBL
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-18_L1
  Grib2_Parameter :
  [ 0 3 18]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Planetary boundary layer height
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Precipitable_water_entire_atmosphere_single_layer
  (time, y, x)
  float32
  ...
  long_name :
  Precipitable water @ Entire atmosphere layer
  units :
  kg.m-2
  abbreviation :
  PWAT
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-3_L200
  Grib2_Parameter :
  [0 1 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Precipitable water
  Grib2_Level_Type :
  200
  Grib2_Level_Desc :
  Entire atmosphere layer
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Pressure_surface
  (time, y, x)
  float32
  ...
  long_name :
  Pressure @ Ground or water surface
  units :
  Pa
  abbreviation :
  PRES
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-0_L1
  Grib2_Parameter :
  [0 3 0]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Pressure
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Pressure_reduced_to_MSL_msl
  (time, y, x)
  float32
  ...
  long_name :
  Pressure reduced to MSL @ Mean sea level
  units :
  Pa
  abbreviation :
  PRMSL
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-1_L101
  Grib2_Parameter :
  [0 3 1]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Pressure reduced to MSL
  Grib2_Level_Type :
  101
  Grib2_Level_Desc :
  Mean sea level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Snow_depth_surface
  (time, y, x)
  float32
  ...
  long_name :
  Snow depth @ Ground or water surface
  units :
  m
  abbreviation :
  SNOD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-1-11_L1
  Grib2_Parameter :
  [ 0 1 11]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Snow depth
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Storm_relative_helicity_height_above_ground_layer
  (time, height_above_ground_layer2, y, x)
  float32
  ...
  long_name :
  Storm relative helicity @ Specified height level above ground layer
  units :
  J/kg
  abbreviation :
  HLCY
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-8_L103_layer
  Grib2_Parameter :
  [0 7 8]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Storm relative helicity
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- Surface_lifted_index_isobaric_layer
  (time, isobaric_layer, y, x)
  float32
  ...
  long_name :
  Surface lifted index @ Isobaric surface layer
  units :
  K
  abbreviation :
  LFT X
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-10_L100_layer
  Grib2_Parameter :
  [ 0 7 10]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Surface lifted index
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Temperature_isobaric
  (time, isobaric1, y, x)
  float32
  ...
  long_name :
  Temperature @ Isobaric surface
  units :
  K
  abbreviation :
  TMP
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-0-0_L100
  Grib2_Parameter :
  [0 0 0]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Temperature
  Grib2_Parameter_Name :
  Temperature
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[280598175 values with dtype=float32]
```
- Temperature_height_above_ground
  (time, height_above_ground3, y, x)
  float32
  ...
  long_name :
  Temperature @ Specified height level above ground
  units :
  K
  abbreviation :
  TMP
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-0-0_L103
  Grib2_Parameter :
  [0 0 0]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Temperature
  Grib2_Parameter_Name :
  Temperature
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Total_cloud_cover_entire_atmosphere
  (time, y, x)
  float32
  ...
  long_name :
  Total cloud cover @ Entire atmosphere
  units :
  %
  abbreviation :
  TCDC
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-6-1_L10
  Grib2_Parameter :
  [0 6 1]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Cloud
  Grib2_Parameter_Name :
  Total cloud cover
  Grib2_Level_Type :
  10
  Grib2_Level_Desc :
  Entire atmosphere
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Total_column_integrated_graupel_entire_atmosphere_single_layer_Mixed_intervals_Maximum
  (time1, y, x)
  float32
  ...
  long_name :
  Total column integrated graupel (Mixed_intervals Maximum) @ Entire atmosphere layer
  units :
  kg.m-2
  abbreviation :
  TCOLG
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-1-74_L200_Imixed_S2
  Grib2_Parameter :
  [ 0 1 74]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Total column integrated graupel
  Grib2_Level_Type :
  200
  Grib2_Level_Desc :
  Entire atmosphere layer
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Total_precipitation_surface_1_Hour_Accumulation
  (time2, y, x)
  float32
  ...
  long_name :
  Total precipitation (1_Hour Accumulation) @ Ground or water surface
  units :
  kg.m-2
  abbreviation :
  APCP
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Accumulation
  Grib_Variable_Id :
  VAR_0-1-8_L1_I1_Hour_S1
  Grib2_Parameter :
  [0 1 8]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Total precipitation
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Accumulation
```
[53165970 values with dtype=float32]
```
- Reflectivity_height_above_ground
  (time, height_above_ground1, y, x)
  float32
  ...
  long_name :
  Reflectivity @ Specified height level above ground
  units :
  dB
  abbreviation :
  REFD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-16-195_L103
  Grib2_Parameter :
  [ 0 16 195]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Forecast Radar Imagery
  Grib2_Parameter_Name :
  Reflectivity
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Composite_reflectivity_entire_atmosphere
  (time, y, x)
  float32
  ...
  long_name :
  Composite reflectivity @ Entire atmosphere
  units :
  dB
  abbreviation :
  REFC
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-16-196_L10
  Grib2_Parameter :
  [ 0 16 196]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Forecast Radar Imagery
  Grib2_Parameter_Name :
  Composite reflectivity
  Grib2_Level_Type :
  10
  Grib2_Level_Desc :
  Entire atmosphere
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Hourly_Maximum_of_Simulated_Reflectivity_at_1_km_AGL_height_above_ground_Mixed_intervals_Maximum
  (time1, height_above_ground1, y, x)
  float32
  ...
  long_name :
  Hourly Maximum of Simulated Reflectivity at 1 km AGL (Mixed_intervals Maximum) @ Specified height level above ground
  units :
  dB
  abbreviation :
  MAXREF
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-16-198_L103_Imixed_S2
  Grib2_Parameter :
  [ 0 16 198]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Forecast Radar Imagery
  Grib2_Parameter_Name :
  Hourly Maximum of Simulated Reflectivity at 1 km AGL
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Lightning_entire_atmosphere
  (time, y, x)
  float32
  ...
  long_name :
  Lightning @ Entire atmosphere
  units :
  non-dim
  abbreviation :
  LTNG
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-17-192_L10
  Grib2_Parameter :
  [ 0 17 192]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Electrodynamics
  Grib2_Parameter_Name :
  Lightning
  Grib2_Level_Type :
  10
  Grib2_Level_Desc :
  Entire atmosphere
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Hourly_Maximum_of_Upward_Vertical_Velocity_in_the_lowest_400hPa_pressure_difference_layer_Mixed_intervals_Maximum
  (time1, pressure_difference_layer2, y, x)
  float32
  ...
  long_name :
  Hourly Maximum of Upward Vertical Velocity in the lowest 400hPa (Mixed_intervals Maximum) @ Level at specified pressure difference from ground to level layer
  units :
  m.s-1
  abbreviation :
  MAXUVV
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-2-220_L108_layer_Imixed_S2
  Grib2_Parameter :
  [ 0 2 220]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Hourly Maximum of Upward Vertical Velocity in the lowest 400hPa
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Hourly_Maximum_of_Downward_Vertical_Velocity_in_the_lowest_400hPa_pressure_difference_layer_Mixed_intervals_Maximum
  (time1, pressure_difference_layer2, y, x)
  float32
  ...
  long_name :
  Hourly Maximum of Downward Vertical Velocity in the lowest 400hPa (Mixed_intervals Maximum) @ Level at specified pressure difference from ground to level layer
  units :
  m.s-1
  abbreviation :
  MAXDVV
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-2-221_L108_layer_Imixed_S2
  Grib2_Parameter :
  [ 0 2 221]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Hourly Maximum of Downward Vertical Velocity in the lowest 400hPa
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Pressure_of_level_from_which_parcel_was_lifted_pressure_difference_layer
  (time, pressure_difference_layer, y, x)
  float32
  ...
  long_name :
  Pressure of level from which parcel was lifted @ Level at specified pressure difference from ground to level layer
  units :
  Pa
  abbreviation :
  PLPL
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-3-200_L108_layer
  Grib2_Parameter :
  [ 0 3 200]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Mass
  Grib2_Parameter_Name :
  Pressure of level from which parcel was lifted
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Best_4_layer_Lifted_Index_pressure_difference_layer
  (time, pressure_difference_layer1, y, x)
  float32
  ...
  long_name :
  Best (4 layer) Lifted Index @ Level at specified pressure difference from ground to level layer
  units :
  K
  abbreviation :
  4LFTX
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-7-193_L108_layer
  Grib2_Parameter :
  [ 0 7 193]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Best (4 layer) Lifted Index
  Grib2_Level_Type :
  108
  Grib2_Level_Desc :
  Level at specified pressure difference from ground to level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Hourly_Maximum_of_Updraft_Helicity_over_Layer_2km_to_5_km_AGL_height_above_ground_layer_Mixed_intervals_Maximum
  (time1, height_above_ground_layer, y, x)
  float32
  ...
  long_name :
  Hourly Maximum of Updraft Helicity over Layer 2km to 5 km AGL (Mixed_intervals Maximum) @ Specified height level above ground layer
  units :
  m2.s-2
  abbreviation :
  MXUPHL
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-7-199_L103_layer_Imixed_S2
  Grib2_Parameter :
  [ 0 7 199]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Thermodynamic stability indices
  Grib2_Parameter_Name :
  Hourly Maximum of Updraft Helicity over Layer 2km to 5 km AGL
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Vertical_u-component_shear_height_above_ground_layer
  (time, height_above_ground_layer3, y, x)
  float32
  ...
  long_name :
  Vertical u-component shear @ Specified height level above ground layer
  units :
  1/s
  abbreviation :
  VUCSH
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-15_L103_layer
  Grib2_Parameter :
  [ 0 2 15]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Vertical u-component shear
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- Vertical_v-component_shear_height_above_ground_layer
  (time, height_above_ground_layer3, y, x)
  float32
  ...
  long_name :
  Vertical v-component shear @ Specified height level above ground layer
  units :
  1/s
  abbreviation :
  VVCSH
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-16_L103_layer
  Grib2_Parameter :
  [ 0 2 16]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Vertical v-component shear
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- Vertical_velocity_geometric_sigma_layer_Mixed_intervals_Average
  (time1, sigma_layer, y, x)
  float32
  ...
  long_name :
  Vertical velocity (geometric) (Mixed_intervals Average) @ Sigma level layer
  units :
  m/s
  abbreviation :
  DZDT
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Average
  Grib_Variable_Id :
  VAR_0-2-9_L104_layer_Imixed_S0
  Grib2_Parameter :
  [0 2 9]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Vertical velocity (geometric)
  Grib2_Level_Type :
  104
  Grib2_Level_Desc :
  Sigma level
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Average
```
[56119635 values with dtype=float32]
```
- Vertically_integrated_liquid_water_VIL_entire_atmosphere
  (time, y, x)
  float32
  ...
  long_name :
  Vertically integrated liquid water (VIL) @ Entire atmosphere
  units :
  kg.m-2
  abbreviation :
  VIL
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-15-3_L10
  Grib2_Parameter :
  [ 0 15 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Radar
  Grib2_Parameter_Name :
  Vertically integrated liquid water (VIL)
  Grib2_Level_Type :
  10
  Grib2_Level_Desc :
  Entire atmosphere
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Visibility_surface
  (time, y, x)
  float32
  ...
  long_name :
  Visibility @ Ground or water surface
  units :
  m
  abbreviation :
  VIS
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-19-0_L1
  Grib2_Parameter :
  [ 0 19 0]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Physical atmospheric Properties
  Grib2_Parameter_Name :
  Visibility
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- Water_equivalent_of_accumulated_snow_depth_surface_1_Hour_Accumulation
  (time2, y, x)
  float32
  ...
  long_name :
  Water equivalent of accumulated snow depth (1_Hour Accumulation) @ Ground or water surface
  units :
  kg.m-2
  abbreviation :
  WEASD
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Accumulation
  Grib_Variable_Id :
  VAR_0-1-13_L1_I1_Hour_S1
  Grib2_Parameter :
  [ 0 1 13]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Moisture
  Grib2_Parameter_Name :
  Water equivalent of accumulated snow depth
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Accumulation
```
[53165970 values with dtype=float32]
```
- Wind_speed_height_above_ground_Mixed_intervals_Maximum
  (time1, height_above_ground, y, x)
  float32
  ...
  long_name :
  Wind speed (Mixed_intervals Maximum) @ Specified height level above ground
  units :
  m/s
  abbreviation :
  WIND
  grid_mapping :
  LambertConformal_Projection
  Grib_Statistical_Interval_Type :
  Maximum
  Grib_Variable_Id :
  VAR_0-2-1_L103_Imixed_S2
  Grib2_Parameter :
  [0 2 1]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Wind speed
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  Maximum
```
[56119635 values with dtype=float32]
```
- Wind_speed_gust_surface
  (time, y, x)
  float32
  ...
  long_name :
  Wind speed (gust) @ Ground or water surface
  units :
  m/s
  abbreviation :
  GUST
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-22_L1
  Grib2_Parameter :
  [ 0 2 22]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  Wind speed (gust)
  Grib2_Level_Type :
  1
  Grib2_Level_Desc :
  Ground or water surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- u-component_of_wind_isobaric
  (time, isobaric1, y, x)
  float32
  ...
  long_name :
  u-component of wind @ Isobaric surface
  units :
  m/s
  abbreviation :
  UGRD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-2_L100
  Grib2_Parameter :
  [0 2 2]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  u-component of wind
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[280598175 values with dtype=float32]
```
- u-component_of_wind_height_above_ground
  (time, height_above_ground2, y, x)
  float32
  ...
  long_name :
  u-component of wind @ Specified height level above ground
  units :
  m/s
  abbreviation :
  UGRD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-2_L103
  Grib2_Parameter :
  [0 2 2]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  u-component of wind
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- u-component_storm_motion_height_above_ground_layer
  (time, height_above_ground_layer1, y, x)
  float32
  ...
  long_name :
  u-component storm motion @ Specified height level above ground layer
  units :
  m/s
  abbreviation :
  USTM
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-27_L103_layer
  Grib2_Parameter :
  [ 0 2 27]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  u-component storm motion
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
- v-component_of_wind_isobaric
  (time, isobaric1, y, x)
  float32
  ...
  long_name :
  v-component of wind @ Isobaric surface
  units :
  m/s
  abbreviation :
  VGRD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-3_L100
  Grib2_Parameter :
  [0 2 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  v-component of wind
  Grib2_Level_Type :
  100
  Grib2_Level_Desc :
  Isobaric surface
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[280598175 values with dtype=float32]
```
- v-component_of_wind_height_above_ground
  (time, height_above_ground2, y, x)
  float32
  ...
  long_name :
  v-component of wind @ Specified height level above ground
  units :
  m/s
  abbreviation :
  VGRD
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-3_L103
  Grib2_Parameter :
  [0 2 3]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  v-component of wind
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[112239270 values with dtype=float32]
```
- v-component_storm_motion_height_above_ground_layer
  (time, height_above_ground_layer1, y, x)
  float32
  ...
  long_name :
  v-component storm motion @ Specified height level above ground layer
  units :
  m/s
  abbreviation :
  VSTM
  grid_mapping :
  LambertConformal_Projection
  Grib_Variable_Id :
  VAR_0-2-28_L103_layer
  Grib2_Parameter :
  [ 0 2 28]
  Grib2_Parameter_Discipline :
  Meteorological products
  Grib2_Parameter_Category :
  Momentum
  Grib2_Parameter_Name :
  v-component storm motion
  Grib2_Level_Type :
  103
  Grib2_Level_Desc :
  Specified height level above ground
  Grib2_Generating_Process_Type :
  Forecast
  Grib2_Statistical_Process_Type :
  UnknownStatType--1
```
[56119635 values with dtype=float32]
```
Attributes: (11)
Originating_or_generating_Center :
US National Weather Service, National Centres for Environmental Prediction (NCEP)
Originating_or_generating_Subcenter :
0
GRIB_table_version :
2,1
Type_of_generating_process :
Forecast
Analysis_or_forecast_generating_process_identifier_defined_by_originating_centre :
High Resolution Rapid Refresh (HRRR)
file_format :
GRIB-2
Conventions :
CF-1.6
history :
Read using CDM IOSP GribCollection v3
featureType :
GRID
_CoordSysBuilder :
ucar.nc2.dataset.conv.CF1Convention
EXTRA_DIMENSION.reftime :
1

Tip: This Dataset, while stored in its native (GRIB2) format, presents itself to Xarray as NetCDF. The THREDDS server automatically translates GRIB to NetCDF.
Notice as well that its horizontal dimensions, 2145 x 1377, differs from the HRRR datasets served via cloud providers such as AWS or Google Cloud (1799 x 1099)! The former is a bit higher in horizontal resolution (2.5 km vs 3 km).

Note that the horizontal dimensions of this Dataset are not longitude/latitude. Instead, they represent distances in km from a central origin.

ds.x

<xarray.DataArray 'x' (x: 2145)>
array([-2763.217 , -2760.6772, -2758.1377, ...,  2676.8267,  2679.3662,
        2681.906 ], dtype=float32)
Coordinates:
  * x        (x) float32 -2.763e+03 -2.761e+03 ... 2.679e+03 2.682e+03
    reftime  datetime64[ns] 2023-01-19T14:00:00
Attributes:
    standard_name:        projection_x_coordinate
    units:                km
    _CoordinateAxisType:  GeoX

xarray.DataArray

'x'

x: 2145

-2.763e+03 -2.761e+03 -2.758e+03 ... 2.677e+03 2.679e+03 2.682e+03

array([-2763.217 , -2760.6772, -2758.1377, ...,  2676.8267,  2679.3662,
        2681.906 ], dtype=float32)

Coordinates: (2)
- x
  (x)
  float32
  -2.763e+03 -2.761e+03 ... 2.682e+03
  standard_name :
  projection_x_coordinate
  units :
  km
  _CoordinateAxisType :
  GeoX
```
array([-2763.217 , -2760.6772, -2758.1377, ...,  2676.8267,  2679.3662,
        2681.906 ], dtype=float32)
```
- reftime
  ()
  datetime64[ns]
  2023-01-19T14:00:00
  standard_name :
  forecast_reference_time
  long_name :
  GRIB reference time
  _CoordinateAxisType :
  RunTime
```
array('2023-01-19T14:00:00.000000000', dtype='datetime64[ns]')
```
Attributes: (3)
standard_name :
projection_x_coordinate
units :
km
_CoordinateAxisType :
GeoX

ds.y

<xarray.DataArray 'y' (y: 1377)>
array([-263.79062, -261.25092, -258.7112 , ..., 3225.7612 , 3228.3008 ,
       3230.8406 ], dtype=float32)
Coordinates:
  * y        (y) float32 -263.8 -261.3 -258.7 ... 3.226e+03 3.228e+03 3.231e+03
    reftime  datetime64[ns] 2023-01-19T14:00:00
Attributes:
    standard_name:        projection_y_coordinate
    units:                km
    _CoordinateAxisType:  GeoY

xarray.DataArray

'y'

y: 1377

-263.8 -261.3 -258.7 -256.2 ... 3.226e+03 3.228e+03 3.231e+03

array([-263.79062, -261.25092, -258.7112 , ..., 3225.7612 , 3228.3008 ,
       3230.8406 ], dtype=float32)

Coordinates: (2)
- y
  (y)
  float32
  -263.8 -261.3 ... 3.231e+03
  standard_name :
  projection_y_coordinate
  units :
  km
  _CoordinateAxisType :
  GeoY
```
array([-263.79062, -261.25092, -258.7112 , ..., 3225.7612 , 3228.3008 ,
       3230.8406 ], dtype=float32)
```
- reftime
  ()
  datetime64[ns]
  2023-01-19T14:00:00
  standard_name :
  forecast_reference_time
  long_name :
  GRIB reference time
  _CoordinateAxisType :
  RunTime
```
array('2023-01-19T14:00:00.000000000', dtype='datetime64[ns]')
```
Attributes: (3)
standard_name :
projection_y_coordinate
units :
km
_CoordinateAxisType :
GeoY

Use Xarray’s `plot.imshow` to display gridded data as an image¶

One of the output grids is surface pressure. We can visualize it as a proxy for surface elevation.

ds.Pressure_surface

<xarray.DataArray 'Pressure_surface' (time: 19, y: 1377, x: 2145)>
[56119635 values with dtype=float32]
Coordinates:
  * x        (x) float32 -2.763e+03 -2.761e+03 ... 2.679e+03 2.682e+03
  * y        (y) float32 -263.8 -261.3 -258.7 ... 3.226e+03 3.228e+03 3.231e+03
    reftime  datetime64[ns] 2023-01-19T14:00:00
  * time     (time) datetime64[ns] 2023-01-19T14:00:00 ... 2023-01-20T08:00:00
Attributes:
    long_name:                       Pressure @ Ground or water surface
    units:                           Pa
    abbreviation:                    PRES
    grid_mapping:                    LambertConformal_Projection
    Grib_Variable_Id:                VAR_0-3-0_L1
    Grib2_Parameter:                 [0 3 0]
    Grib2_Parameter_Discipline:      Meteorological products
    Grib2_Parameter_Category:        Mass
    Grib2_Parameter_Name:            Pressure
    Grib2_Level_Type:                1
    Grib2_Level_Desc:                Ground or water surface
    Grib2_Generating_Process_Type:   Forecast
    Grib2_Statistical_Process_Type:  UnknownStatType--1

xarray.DataArray

'Pressure_surface'

time: 19
y: 1377
x: 2145

...
```
[56119635 values with dtype=float32]
```

Coordinates: (4)

x
(x)
float32
-2.763e+03 -2.761e+03 ... 2.682e+03
standard_name :
projection_x_coordinate
units :
km
_CoordinateAxisType :
GeoX
```
array([-2763.217 , -2760.6772, -2758.1377, ...,  2676.8267,  2679.3662,
        2681.906 ], dtype=float32)
```
y
(y)
float32
-263.8 -261.3 ... 3.231e+03
standard_name :
projection_y_coordinate
units :
km
_CoordinateAxisType :
GeoY
```
array([-263.79062, -261.25092, -258.7112 , ..., 3225.7612 , 3228.3008 ,
       3230.8406 ], dtype=float32)
```
reftime
()
datetime64[ns]
2023-01-19T14:00:00
standard_name :
forecast_reference_time
long_name :
GRIB reference time
_CoordinateAxisType :
RunTime
```
array('2023-01-19T14:00:00.000000000', dtype='datetime64[ns]')
```

time

(time)

datetime64[ns]

2023-01-19T14:00:00 ... 2023-01-...

standard_name :: time
long_name :: GRIB forecast or observation time
_CoordinateAxisType :: Time

array(['2023-01-19T14:00:00.000000000', '2023-01-19T15:00:00.000000000',
       '2023-01-19T16:00:00.000000000', '2023-01-19T17:00:00.000000000',
       '2023-01-19T18:00:00.000000000', '2023-01-19T19:00:00.000000000',
       '2023-01-19T20:00:00.000000000', '2023-01-19T21:00:00.000000000',
       '2023-01-19T22:00:00.000000000', '2023-01-19T23:00:00.000000000',
       '2023-01-20T00:00:00.000000000', '2023-01-20T01:00:00.000000000',
       '2023-01-20T02:00:00.000000000', '2023-01-20T03:00:00.000000000',
       '2023-01-20T04:00:00.000000000', '2023-01-20T05:00:00.000000000',
       '2023-01-20T06:00:00.000000000', '2023-01-20T07:00:00.000000000',
       '2023-01-20T08:00:00.000000000'], dtype='datetime64[ns]')

Attributes: (13)
long_name :
Pressure @ Ground or water surface
units :
Pa
abbreviation :
PRES
grid_mapping :
LambertConformal_Projection
Grib_Variable_Id :
VAR_0-3-0_L1
Grib2_Parameter :
[0 3 0]
Grib2_Parameter_Discipline :
Meteorological products
Grib2_Parameter_Category :
Mass
Grib2_Parameter_Name :
Pressure
Grib2_Level_Type :
1
Grib2_Level_Desc :
Ground or water surface
Grib2_Generating_Process_Type :
Forecast
Grib2_Statistical_Process_Type :
UnknownStatType--1

Use Xarray to generate an image, as opposed to a filled contour plot, for the first time in the Dataset.

ds.Pressure_surface.isel(time1=0).plot.imshow(figsize=(15,10))

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Input In [10], in <cell line: 1>()
----> 1 ds.Pressure_surface.isel(time1=0).plot.imshow(figsize=(15,10))

File /knight/anaconda_aug22/envs/aug22_env/lib/python3.10/site-packages/xarray/core/dataarray.py:1291, in DataArray.isel(self, indexers, drop, missing_dims, **indexers_kwargs)
   1286     return self._from_temp_dataset(ds)
   1288 # Much faster algorithm for when all indexers are ints, slices, one-dimensional
   1289 # lists, or zero or one-dimensional np.ndarray's
-> 1291 variable = self._variable.isel(indexers, missing_dims=missing_dims)
   1292 indexes, index_variables = isel_indexes(self.xindexes, indexers)
   1294 coords = {}

File /knight/anaconda_aug22/envs/aug22_env/lib/python3.10/site-packages/xarray/core/variable.py:1223, in Variable.isel(self, indexers, missing_dims, **indexers_kwargs)
   1199 """Return a new array indexed along the specified dimension(s).
   1200 
   1201 Parameters
   (...)
   1219     indexer, in which case the data will be a copy.
   1220 """
   1221 indexers = either_dict_or_kwargs(indexers, indexers_kwargs, "isel")
-> 1223 indexers = drop_dims_from_indexers(indexers, self.dims, missing_dims)
   1225 key = tuple(indexers.get(dim, slice(None)) for dim in self.dims)
   1226 return self[key]

File /knight/anaconda_aug22/envs/aug22_env/lib/python3.10/site-packages/xarray/core/utils.py:850, in drop_dims_from_indexers(indexers, dims, missing_dims)
    848     invalid = indexers.keys() - set(dims)
    849     if invalid:
--> 850         raise ValueError(
    851             f"Dimensions {invalid} do not exist. Expected one or more of {dims}"
    852         )
    854     return indexers
    856 elif missing_dims == "warn":
    857 
    858     # don't modify input

ValueError: Dimensions {'time1'} do not exist. Expected one or more of ('time', 'y', 'x')

WARNING: A quirk in how a THREDDS data server interprets a GRIB dataset means that the coordinate variable names may change unpredictabily from run to run. In this case, the time dimension was named time1. When you run this notebook, the dimension name might also be time1, but it could be something else ... such as time or time2 Modify the cell above if this occurs.

Tip: Rather than creating filled contours, we have used Xarray's Matplotlib interface to create an image map of surface pressure. Its resolution is the same as the dataset ... in this case, approximately 2.5 km. It fits the definition of what is called raster data.

Note: But there exist other rasterized representations of elevation ... at even higher resolutions ... that are in a particular image format (tiff). Since we never expect these elevations to change (except on very long time scales), we can use these static datasets to complement our visualizations.

Use Xarray’s `open_rasterio` method to open high-resolution elevation data¶

Natural Earth, the same source that Cartopy utilizes for many of the background features we have used, also provides raster datasets for download. The medium and high-resolution manually-shaded relief files can be accessed from their location in the course data directory.

ds50m = xr.open_rasterio('/spare11/atm533/data/raster/MSR_50M/MSR_50M.tif')
ds10m = xr.open_rasterio('/spare11/atm533/data/raster/US_MSR_10M/US_MSR.tif')

/tmp/ipykernel_1021647/2329449947.py:1: DeprecationWarning: open_rasterio is Deprecated in favor of rioxarray. For information about transitioning, see: https://corteva.github.io/rioxarray/stable/getting_started/getting_started.html
  ds50m = xr.open_rasterio('/spare11/atm533/data/raster/MSR_50M/MSR_50M.tif')
/tmp/ipykernel_1021647/2329449947.py:2: DeprecationWarning: open_rasterio is Deprecated in favor of rioxarray. For information about transitioning, see: https://corteva.github.io/rioxarray/stable/getting_started/getting_started.html
  ds10m = xr.open_rasterio('/spare11/atm533/data/raster/US_MSR_10M/US_MSR.tif')

Examine these Datasets¶

ds50m

<xarray.DataArray (band: 1, y: 5400, x: 10800)>
[58320000 values with dtype=uint8]
Coordinates:
  * band     (band) int64 1
  * y        (y) float64 89.98 89.95 89.92 89.88 ... -89.88 -89.92 -89.95 -89.98
  * x        (x) float64 -180.0 -179.9 -179.9 -179.9 ... 179.9 179.9 179.9 180.0
Attributes:
    transform:               (0.03333333333333, 0.0, -179.99999999999997, 0.0...
    crs:                     +init=epsg:4326
    res:                     (0.03333333333333, 0.03333333333333)
    is_tiled:                0
    nodatavals:              (nan,)
    scales:                  (1.0,)
    offsets:                 (0.0,)
    AREA_OR_POINT:           Area
    TIFFTAG_DATETIME:        2015:01:13 09:19:11
    TIFFTAG_RESOLUTIONUNIT:  2 (pixels/inch)
    TIFFTAG_SOFTWARE:        Adobe Photoshop CC 2014 (Macintosh)
    TIFFTAG_XRESOLUTION:     342.85699
    TIFFTAG_YRESOLUTION:     342.85699

xarray.DataArray

band: 1
y: 5400
x: 10800

...
```
[58320000 values with dtype=uint8]
```

Coordinates: (3)

band
(band)
int64
1
```
array([1])
```

(y)

float64

89.98 89.95 89.92 ... -89.95 -89.98

array([ 89.983333,  89.95    ,  89.916667, ..., -89.916667, -89.95    ,
       -89.983333])

(x)

float64

-180.0 -179.9 ... 179.9 180.0

array([-179.983333, -179.95    , -179.916667, ...,  179.916667,  179.95    ,
        179.983333])

Attributes: (13)
transform :
(0.03333333333333, 0.0, -179.99999999999997, 0.0, -0.03333333333333, 90.0)
crs :
+init=epsg:4326
res :
(0.03333333333333, 0.03333333333333)
is_tiled :
0
nodatavals :
(nan,)
scales :
(1.0,)
offsets :
(0.0,)
AREA_OR_POINT :
Area
TIFFTAG_DATETIME :
2015:01:13 09:19:11
TIFFTAG_RESOLUTIONUNIT :
2 (pixels/inch)
TIFFTAG_SOFTWARE :
Adobe Photoshop CC 2014 (Macintosh)
TIFFTAG_XRESOLUTION :
342.85699
TIFFTAG_YRESOLUTION :
342.85699

ds10m

<xarray.DataArray (band: 1, y: 9493, x: 12578)>
[119402954 values with dtype=uint8]
Coordinates:
  * band     (band) int64 1
  * y        (y) float64 7.56e+06 7.559e+06 7.558e+06 ... 6.678e+05 6.671e+05
  * x        (x) float64 -1.492e+07 -1.492e+07 ... -5.789e+06 -5.788e+06
Attributes:
    transform:               (726.0672549487241, 0.0, -14920200.0, 0.0, -726....
    crs:                     +init=epsg:3857
    res:                     (726.0672549487241, 726.1428270486623)
    is_tiled:                0
    nodatavals:              (nan,)
    scales:                  (1.0,)
    offsets:                 (0.0,)
    AREA_OR_POINT:           Area
    TIFFTAG_DATETIME:        2015:12:30 08:08:29
    TIFFTAG_RESOLUTIONUNIT:  2 (pixels/inch)
    TIFFTAG_SOFTWARE:        Adobe Photoshop CC 2015 (Macintosh)
    TIFFTAG_XRESOLUTION:     350
    TIFFTAG_YRESOLUTION:     350

xarray.DataArray

band: 1
y: 9493
x: 12578

...
```
[119402954 values with dtype=uint8]
```

Coordinates: (3)

band
(band)
int64
1
```
array([1])
```

(y)

float64

7.56e+06 7.559e+06 ... 6.671e+05

array([7559636.928586, 7558910.785759, 7558184.642932, ...,  668541.499895,
        667815.357068,  667089.214241])

(x)

float64

-1.492e+07 ... -5.788e+06

array([-14919836.966373, -14919110.899118, -14918384.831863, ...,
        -5789541.235392,  -5788815.168137,  -5788089.100882])

Attributes: (13)
transform :
(726.0672549487241, 0.0, -14920200.0, 0.0, -726.1428270486623, 7560000.0)
crs :
+init=epsg:3857
res :
(726.0672549487241, 726.1428270486623)
is_tiled :
0
nodatavals :
(nan,)
scales :
(1.0,)
offsets :
(0.0,)
AREA_OR_POINT :
Area
TIFFTAG_DATETIME :
2015:12:30 08:08:29
TIFFTAG_RESOLUTIONUNIT :
2 (pixels/inch)
TIFFTAG_SOFTWARE :
Adobe Photoshop CC 2015 (Macintosh)
TIFFTAG_XRESOLUTION :
350
TIFFTAG_YRESOLUTION :
350

We now have two Xarray DataArray objects. They are three-dimensional (band, y, and x), with the new dimension called band. There is only one band in each of these data arrays, so we will just pass its one index (0) directly to imshow. Note the horizontal dimemsions … in both cases, quite a bit higher than the already high-resolution HRRR grid we viewed above. What parts of the world do they represent?

ds50m.sel(band=1).plot.imshow(figsize=(15,10))

<matplotlib.image.AxesImage at 0x14c696e8c7c0>

ds10m.sel(band=1).plot.imshow(figsize=(15,10))

<matplotlib.image.AxesImage at 0x14c69674f820>

Tip: Notice the x- and y-axis labels. What do you think they represent? Look at the attributes for both of these data arrays for more info. Particularly notice the `crs` (Coordinate Reference System) attributes.
We'll explore these georeferenced TIFF (tagged image file format) images in more detail in subsequent notebooks!

ds10m.crs

'+init=epsg:3857'

Close the file handles so they don’t stay resident in memory.¶

ds.close()
ds10m.close()
ds50m.close()

Summary¶

We can access real-time NWP data via the Unidata THREDDS server
THREDDS automatically translates data in supported formats (such as GRIB) into NetCDF.
Gridded data arrays are a type of raster data.
Matplotlib’s imshow method displays raster data as an image.
A frequently-used image format is tiff.
TIFFS can be geo-referenced, making them very useful in map-based visualizations.

What’s Next?¶

In the next notebook, we’ll use our geo-referenced TIFF as a map layer and overlay NWP data on top of it.

Resources and References¶

Raster data (from Data Carpentry’s Geospatial course)
TIFF definition (Wikipedia)
Python’s Raster library (Rasterio)

Plotting archived HRRR data: 1km reflectivity

Rasters 2: Overlays

By Kevin Tyle with help from the Project Pythia community
© Copyright 2022.

All code in this course is licensed under Apache 2.0. All other non-code content is licensed under Creative Commons BY 4.0 (CC BY 4.0). We want your feedback! See our Contributor's Guide.

ATM433/533 Fall 2022

Rasters 1: Intro to raster data

Contents

Rasters 1: Intro to raster data¶

Overview¶

Prerequisites¶

Imports¶

Access real-time NWP data from Unidata’s THREDDS server¶

Use Xarray’s plot.imshow to display gridded data as an image¶

Use Xarray’s open_rasterio method to open high-resolution elevation data¶

Examine these Datasets¶

Close the file handles so they don’t stay resident in memory.¶

Summary¶

What’s Next?¶

Resources and References¶

Use Xarray’s `plot.imshow` to display gridded data as an image¶

Use Xarray’s `open_rasterio` method to open high-resolution elevation data¶