Data access
The weather forecast model output is available as NetCDF files on https://thredds.met.no/thredds/metno.html and the files follow the NetCDF/CF conventions. This page also documents how to navigate and access the data archived here. This page also documents how to access subsets of these files (So as to not have to download multiple GB of data)
Note also, that all communication to the thredds-server at Met requires a HTTPS connection, any HTTP-request reply with http error code 410: (410 Gone).
When accesing the Weather Forecasts directory, the following screen greets you:
For how to access the file itself see Subsetting
Following are some examples of how to access the files from the thredds-server using the OPeNDAP-protocol. There is also an option to download using a HTTPS-Server, though this is not adviced due to the file sizes involved
See Python