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:

• ECMWF global leadership in precipitation forecasting has fallen to a 3rd place (QED, 29 Septemberr 2026)
• ECMWF is a recognised global leader in Weather + Atmospheric/Surface reanalysis (Rabier et al. 2025)
• ECMWF precipitation is only a forecast field (unlike T2m that has a dedicated 2D-analysis) and it has large documented errors (Lavers et al. 2021)
• ECWMF is investing in CONVX improving precipitiation, 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) yet 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:

• Draft PLAN
• Draft PPTX

Proposed start: Q4-2026