Gridded global Precipitation for Hydrology applications.
A global gridded precipitation is a high-relevance high-priority development for a number of applications at ECMWF, particularly in 2026-2027, there are 5-key motivations:
- ECMWF has a recognised global leadership in Weather + Atmospheric/Surface reanalysis (Rabier et al. 2025)
- ECMWF global leadership in precipitation forecasting has stably fallen to a 3rd place (QED, 29 Septemberr 2026)
- ECMWF precipitation is only a forecast field (unlike T2m having a dedicated 2D-analysis) and with large documented errors (Lavers et al. 2021)
- ECWMF is investing in CONVX package, and full Hydrological Coupling (CaMa-Flood+), yet without a reliable verifying analysis for precipitation
- ECMWF is largely investing in AI-driven forecasting (AIFS, aiLand, AIFL) missing a crucial precipitation high-quality field for training/forcing.
For all the reasons above a precipitation analysis project is timely and relevant and a proposal is drafted:
Proposed period: Q4-2026 to Q4-2027
Proposed kick-off: 5 November 2026
Proposed international task-force: ECCC (CaPA team), MetNo (GridPP + Bris team), SMHI (Clim team), ECMWF (Hydro-Land-Physics team)