GDO Indicator for Forecasting Unusually Wet and Dry Conditions SPI-1 based on the multi-system forecast (version 2.0.0)

This layer provides an early warning of persistent extreme wet and dry precipitation events over the world derived from 1-month Standardized Precipitation Index (SPI-1). The forecasts of SPI are derived from the forecasted precipitation provided by the contributing centers to the Copernicus C3S probabilistic multi-system seasonal forecast ensemble. The early warning is plotted only when and where the forecast is considered robust (with at least 40% of the ensemble members associated with extreme forecasts) and associated with relative extreme values (SPI lower than -1). The colors indicate the return period of the intensity and the coherency of the ensemble members of the forecast model according to the reference period that spans from 1993 to 2016.