***** Draft ********

This page aims at documenting the steps to follow when a data provider plans to implement a new version of the model

Test data

First of all, the archive centres welcome to have some test data in advance, so the ingestion suites can be adapted.

Obviously, some changes are more disruptive than others:

1. If it's only a change of resolution or a meteorological change, we do not need test data.
2. if there is a change in the configuration, then we need to have test data and documentation about the new configuration. This could be:
   • change to the frequency of time-steps or extend/shorten the length of the forecast
   • addition/removal of parameters
   • change to the number of ensembles
   • change to the frequency of the forecast (eg, from once a week to twice a week)

For the second type of changes, we welcome to have test data in advance. This is achieved by naming files as test instead of prod, and by setting in the GRIB header Production status of data to 7:

6: S2S operational products
7: S2S test products

Documentation

For the second type of changes, we need to adapt the Models page

In the description of each individual model, we suggest to keep the previous description, with an indication of dates for which this configuration was valid, and create a new page with the new configuration. As an example, one can follow what has been done for ECMWF Model, which has changed several times.