New year edge case error: Daily prediction generation

[bnubald]

Issue

When attempting to generate daily forecasts using the run_era5_forecast.sh over the first week of a year, it fails with the following error (Script run on 5th/6th of Jan 2025):

$ ./run_era5_forecast.sh atmos23

Traceback (most recent call last):
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/file_manager.py", line 209, in _acquire_with_cache_info
    file = self._cache[self._key]
           ~~~~~~~~~~~^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/lru_cache.py", line 55, in __getitem__
    value = self._cache[key]
            ~~~~~~~~~~~^^^^^
KeyError: [<class 'netCDF4._netCDF4.Dataset'>, ('/data/hpcdata/users/username/icenet-daily-forecast-generation/data/era5/south/tas/2025.nc',), 'r', (('clobber', True), ('diskless', False), ('format', 'NETCDF4'), ('persist', False)), '569e43f1-2646-4b70-8b7b-4178558efa60']

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/api.py", line 541, in open_dataset
    backend_ds = backend.open_dataset(
                 ^^^^^^^^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/netCDF4_.py", line 578, in open_dataset
    store = NetCDF4DataStore.open(
            ^^^^^^^^^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/netCDF4_.py", line 382, in open
    return cls(manager, group=group, mode=mode, lock=lock, autoclose=autoclose)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/netCDF4_.py", line 329, in __init__
    self.format = self.ds.data_model
                  ^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/netCDF4_.py", line 391, in ds
    return self._acquire()
           ^^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/netCDF4_.py", line 385, in _acquire
    with self._manager.acquire_context(needs_lock) as root:
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/contextlib.py", line 137, in __enter__
    return next(self.gen)
           ^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/file_manager.py", line 197, in acquire_context
    file, cached = self._acquire_with_cache_info(needs_lock)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/hpcdata/users/username/miniconda3/envs/icenet0.2.9_dev/lib/python3.11/site-packages/xarray/backends/file_manager.py", line 215, in _acquire_with_cache_info
    file = self._opener(*self._args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "src/netCDF4/_netCDF4.pyx", line 2353, in netCDF4._netCDF4.Dataset.__init__
  File "src/netCDF4/_netCDF4.pyx", line 1963, in netCDF4._netCDF4._ensure_nc_success
FileNotFoundError: [Errno 2] No such file or directory: b'/data/hpcdata/users/username/icenet-daily-forecast-generation/data/era5/south/tas/2025.nc'

Solution

Problem caused by:

icenet-pipeline/run_era5_forecast.sh

Line 22 in 3db92a0

FORECAST_INIT=`python -c 'import xarray as xr; print(str(xr.open_dataset("data/era5/'$HEMI'/tas/'${DATE_RANGE:0:4}'.nc").time.values.max())[0:10])'`

The DATE_RANGE here:

icenet-pipeline/run_era5_forecast.sh

Line 16 in 3db92a0

DATE_RANGE="`date +%Y-1-1` `date +%F`"

resolves to 2025-1-1 2025-1-6

And, it tries to load: data/era5/south/tas/2025.nc, but due to the ~5 day lag in ERA5 data availability, this file does not yet exist, and so, shows this error.

If this happens, it should try to figure out the latest available date to initialise forecast from using the previous year's file instead.