The WMO LC-SSPMME for sub-seasonal predictions builds on the legacy left by the S2S project (link) and relies on the S2S data base (link). Although the S2S project has completed, several operational and research centres continue to provide their forecast and re-forecast to the S2S archive for at least another 5 years.
The S2S archive page (link) is constantly updated and displays information about the forecast data archived and about the models (link) that have produced it. The S2S forecast is available to the public with a latency of 3 weeks.
Currently eight centres (referred as contributing centres) have agreed to provide the WMO LC-SSPMME with their forecast without the 3-weeks latency imposed by the S2S data policy. The LC publish the forecast charts (individual and multi-model) once a week. The charts, based on the forecasts initialized around Thursday, will be updated every Monday to give enough time for data to arrive.
Since the LC provides a timelier service, an updated list of contact point in case of problem with reception/encoding of data is in used.