Modernizing Flood Forecast Data Access with the CEMS Early Warning Data Store (EWDS)

The Early Warning Data Store (EWDS), introduced by the European Centre for Medium-Range Weather Forecasts (ECMWF), represents a major advancement in the Copernicus Emergency Management Service (CEMS). Launched on 26 September 2024, the EWDS is a modern, user-focused system for hosting and disseminating CEMS-Flood datasets from the European and Global Flood Awareness Systems (EFAS and GloFAS), which provide vital data for flood forecasting, disaster preparedness, and water resource management.
In 2024, the Early Warning Data Store (EWDS) registered 18,003 users, with over than 20,138 completed requests for EFAS and GloFAS datasets from 42 distinct countries. The total data retrieved amounted to approximately 3,029.72 TB, distributed across different products. The EWDS hosts EFAS and GloFAS datasets in GRIB and NetCDF formats, including historical data, forecasts, reforecasts, seasonal forecasts, and seasonal reforecasts. Auxiliary datasets support flood forecasting and hydrological analysis. For EFAS and GloFAS, these include datasets related to upstream areas, elevation, soil characteristics, and flood thresholds.
Accessing these datasets is simplified through a modern web interface and an Open Geospatial Consortium (OGC)-compliant API, ensuring compatibility with diverse user needs. Following FAIR principles (Findable, Accessible, Interoperable, Reusable), the EWDS makes its data easy to find, access, and use across different platforms. Improvements to previous versions include flexible data download options and precise region-of-interest bounding box specifications. Supported by ECMWF's robust Meteorological Archival and Retrieval System (MARS) infrastructure, the EWDS ensures efficient data extraction and delivery, even for large-scale requests.
A key feature of the EWDS is its integration with Earthkit, ECMWF’s open-source Python project designed to simplify data workflows. Earthkit provides tools for data access, processing, analysis, and visualization, using libraries such as numpy, pandas, and matplotlib. Earthkit-Hydro, currently under development, will extend these capabilities, offering customized solutions for hydrological research and flood risk management. Additionally, there is comprehensive documentation and a user support and feedback service. This presentation will introduce the technological innovations of the EWDS, its user-focused capabilities, and its role in advancing global flood forecasting and risk management.