The World Weather Research Programme (WWRP) and the World Climate Research Programme (WCRP) Sub-seasonal to Seasonal Prediction Project (S2S) was launched in November 2013, with the primary goals of improving forecast skill and understanding the dynamics and climate drivers on the sub-seasonal to seasonal timescale (from 2 weeks to a season). The S2S project has a special emphasis on high-impact weather events, developing coordination among operational centres, and on promoting uptake of S2S information by the applications communities. A key motivation of S2S was to capitalize on the expertise of the weather and climate research communities and WMO/WWRP/WCRP programmes - filling the gap between medium-range and seasonal forecasting - to address issues of importance to the Global Framework for Climate Services (GFCS).

CMA, one of the two S2S data archiving center, is responsible for collecting the S2S data from all data providers, performing basic quality check, archiving, and providing data service. The CMA S2S database is operation and maintenance by China Meteorological Data Service Center (CMDC).

China Meteorological Data Service Center, is an important component of the underlying national science and technology platform and a main portal application system of meteorological cloud. It is an authoritative and unified shared service platform for China Meteorological Administration to open its meteorological data resources to domestic and global users.