Decadal climate prediction, where climate models are initialized with the contemporaneous state of the Earth system and run for a decade into the future, represents a new source of near-term climate information to better inform decisions and policies across key climate-sensitive sectors
This paper illustrates the potential usefulness of such predictions for building a climate service for agricultural needs
In particular, we assess the forecast quality of multi-model climate predictions in estimating two user-relevant drought indices, Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI), at multi-annual timescales during European summer
The S2S and S2D communities share common scientific and technical challenges: forecast initialization and ensemble generation; initialization shock and drift; understanding the onset of model systematic errors; bias correction, calibration, and forecast quality assessment; model resolution; atmosphere–ocean coupling; sources and expectations for predictability; and linking research, operational forecasting, and end-user needs
Performance of S2D predictions is strongly tied to initialization of model components beyond the lower atmosphere. For example, stratospheric initial conditions are a source of seasonal winter NAO skill, and ocean initial conditions are crucial for skillfully predicting ENSO, as well as decadal variability in the subpolar North Atlantic
Many decisions are made on the S2S forecasting time scale, which sits between weather forecasts and S2D climate outlooks; therefore, the continued development of S2S forecasts has the potential to benefit many sectors of society