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)
The WMO has approved the GRIB-format for efficiently transmitting meteorological gridded data, so this is one of the preferred formats for exchanging data between meteorological services. GRIB has been around for some 35 years - since before the Internett and the PC was invented - with minimal changes to the format.
Being able to read GRIB data yourself, gives you the capacity to access gridded meteorological information from the weather services on the lowest possible level. This can be an advantage if you are looking for a reliable starting point for your data processing chain, which you plan to run with as little interruption as possible for the next decades to come.
Some basic receipts for installing and running the Fimex software for reading and interpolation GRIB2 files on Ubuntu are readily available here.