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I'm trying to extract a timeseries for a single point from one of the EFAS datasets. I can retrieve the data from the catalogue:

print(data)

which gives the following output:

<xarray.DataArray 'snow_amount' (time: 152, y: 950, x: 1000)>
dask.array<shape=(152, 950, 1000), dtype=float32, chunksize=(48, 950, 1000)>
Coordinates:
  * y           (y) float32 752500.0 757500.0 762500.0 ... 5492500.0 5497500.0
  * x           (x) float32 2502500.0 2507500.0 ... 7492500.0 7497500.0
  * time        (time) datetime64[ns] 2012-01-01T06:00:00 ... 2012-05-31T06:00:00
    leadtime    timedelta64[ns] ...
    surface     int64 ...
    lat         (y, x) float64 dask.array<shape=(950, 1000), chunksize=(950, 1000)>
    lon         (y, x) float64 dask.array<shape=(950, 1000), chunksize=(950, 1000)>
    valid_time  (time) datetime64[ns] dask.array<shape=(152,), chunksize=(48,)>
Attributes:
    long_name:                Snow Amount
    units:                    kg m^-2
    grid_mapping:             lambert_azimuthal_equal_area
    standard_name:            surface_snow_amount
    cell_methods:             area: mean where land time: mean
    cell_measures:            area: areacella
    comment:                  where land over land, this is computed as the m...
    type:                     real
    Conventions:              CF-1.7
    institution:              European Centre for Medium-Range Weather Forecasts
    history:                  2019-10-17T08:37:36 GRIB to CDM+CF via cfgrib-0...
    grid_mapping_short_name:  laean
    source:                   EFAS

However, following the extract time series example, this:

data_sel = ct.geo.extract_point(data, lon=lon, lat=lat)

gives me an error:

Traceback (most recent call last):
  File "/opt/cdstoolbox/cdscompute/cdscompute/cdshandlers/services/handler.py", line 49, in handle_request
    result = cached(context.method, proc, context, *context.args, **context.kwargs)
(...)

  File "/usr/local/lib/python3.6/site-packages/xarray/core/indexing.py", line 207, in get_dim_indexers
    % invalid)
ValueError: dimensions or multi-index levels ['lon', 'lat'] do not exist

This is, of course, not particularly helpful. Googling this as an xarray error message suggests that the problem could be that the lon/lat coordinates are in fact 2-dimensional, but I'm stumped as to what the solution then would be. I tried several examples of indexing xarray DataArrays but none of them seem to work as expected. The cube.select function gives me the same error message as above.  The function geo.make_regular seemed promising, but throws up a key error on 'laean'.

How can I perform this basic task, which is to select the data for a single point based on it's lat/lon value? 

Many thanks in advance for any pointers!