This page documents the steps to follow when a data provider plans to implement changes to their system, such as a new version of their model or a change in the configuration

There can be two types of changes:

In both cases, data providers must update the documentation with what has changed, so users are able to follow the history of a model

Changes to the configuration

When a change affects the number of fields, we ask data providers to:

• Notify in advance ECMWF and CMA,
• Provide test data (if required)
• Update the documentation.

Notify in advance ECMWF and CMA

Send an e-mail to s2s.support@lists.ecmwf.int. describing the change.

Provide test data (if required)

If the change affects how fields are encoded, it is recommended to test the new encoding by ingesting test data in the S2S database, so ECMWF and CMA could adapt the ingestion suites if required.

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

Once you have a full cycle of test data (whether real-time and/or reforecast) we ask you to contact s2s.support@lists.ecmwf.int.

Update the documentation

Models are documented in two places:

• Models summary, which contains an overview of the latest configuration
• A page describing in detail each model (for example, changes in ECMWF Model), where one would keep details of previous configurations, in particular the date of the change.

For changes to the configuration for the same model (increase frequency, extend reforecast, addition of parameters), a note could be added to the model page (for example, see changes in UKMO Model)