RuntimeError: Unable to load latest weather data for GFS

[git-akihakune]

Describe the bug

Running the code in Colab Notebook preview led to an error.

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
[<ipython-input-17-71fdef7bdc29>](https://localhost:8080/#) in <module>()
----> 1 Env.setAtmosphericModel(type="Forecast", file="GFS")

[/usr/local/lib/python3.7/dist-packages/rocketpy/Environment.py](https://localhost:8080/#) in setAtmosphericModel(self, type, file, dictionary, pressure, temperature, wind_u, wind_v)
    935                 if not success:
    936                     raise RuntimeError(
--> 937                         "Unable to load latest weather data for GFS through " + file
    938                     )
    939             elif file == "FV3":

RuntimeError: Unable to load latest weather data for GFS through https://nomads.ncep.noaa.gov/dods/gfs_0p25/gfs20220717/gfs_0p25_06z

To Reproduce

Just run the default code in the preview.

Expected behavior

It's expected to run the demo smoothly.

Screenshots

Additional context

Checking the GrADS Data Server, indeed, I'm currently not seeing any "gfs20220717" dir. Maybe fixing the link can solve this issue.

[giovaniceotto]

@git-akihakune Thanks for letting us know that you are having an issue. We recently became aware of this and it seems to be a problem relating the netCDF4 library and Colab.

We have not been able to reproduce the error locally so far. I will perform further investigations and let you know.

Regarding you not seeing the any "gfs20220717", this is because RocketPy tries to retrieve data from each day up until 10 days in the past. This is done so that previous forecasts can be retrieved in case there is a temporary problem with GFS.

[giovaniceotto]

I have just confirmed that running on a linux server (GitHub Codespaces) works properly. It really seems to be a problem specific to Google Colab.

Furthermore, I have tested a simple netCDF4 example using Colab and also got an error. You can see the example here: https://colab.research.google.com/drive/17juZulxoz8sahoDJVuU4uOMSnBC_xXDA?usp=sharing

On other systems, the example runs fine.

This maybe a related issue: Unidata/netcdf4-python#753

[giovaniceotto]

I have created a new issue on netCDF4's repo for us to track while we investigate this: Unidata/netcdf4-python#1179

[giovaniceotto]

@git-akihakune I found a quick workaraound: installing an earlier version of netCDF4 solves the problem for me.

You can try by running !pip install "netCDF4<1.6.0" in Colab and checking if it also solves your issue.

[git-akihakune]

The workaround was great. I've tested on a few different Colab notebooks and no error was reported.

As for this issue, I suggest leaving it open until the problem is entirely solved.

[Gui-FernandesBR]

As for this issue, I suggest leaving it open until the problem is entirely solved.

Agreed!!

[OliverKillane]

Env.setAtmosphericModel(type='Forecast', file='GFS', dictionary='NOAA')

Having the same problem here:

With netCDF4-1.6.1 the same error (date in url different)

With netcdf4-1.5.8 it works