ECMWF has implemented a new state-of-the-art data access infrastructure to host the Climate and Atmospheric Data Stores (CDS and ADS, respectively). All layers of the infrastructure are being modernised: the front-end web interface, the back-end software engine, and the underlying cloud infrastructure hosting the service and core data repositories.

As part of this development, a new data store for the Copernicus Emergency Management Service (CEMS) has been created. The CEMS Early Warning Data Store (EWDS) will host all the historical and forecast information for floods and forest fires at European and Global levels. Users are encouraged to migrate their accounts and scripts to the new EWDS Beta before 26 September 2024, when the system will become operational.

For more information, Please read: CEMS Early Warning Data Store (EWDS) is now live!

Updates to the EWDS documentation are ongoing as the implementation takes place.

There are two ways to download and interact with CEMS-Flood (EFAS/GloFAS) data on the EWDS. The following pages will guide you through each process. 

  1. Through a simple form on the "Download data" tab within the main dataset overview page, where you can select model versions, variables and times required.
  2. Programmatic access through the Python EWDS API


Using the 'Download Data' tab on the Early Warning Data Store

You can watch this quick video tutorial on how to access CEMS-Flood data using the CDS 'Data Download' tab on YouTube.

Or follow the step-by-step guide below.

  • On the EWDS homepage, enter the dataset of interest into the search bar.

  • The next page lists the datasets returned for your search criteria. You can narrow your search by using the filters on the left-hand side.

  • Click on the heading of the dataset you are interested in. In this example, we chose 'River discharge and related historical data from the European Flood Awareness System'. On the 'Overview' tab you will see details such as the data description and technical information about the data, for example, variables, coverage, resolution, etc. On the right side you will see a list of links with supporting documentation and links to related datasets. On the 'Documentation' tab you will see a list of links to relevant documentation, e.g. CEMS-Flood wiki pages, web interface, etc.

  • Click the 'Download tab'. This will bring you to the EWDS online download form for your chosen dataset.
    Select the options using the radio buttons. Make sure you make a selection for all mandatory fields.

  • The EWDS now provides the option to select the whole available region or a geographical sub-region extraction (i.e. area cropping) on the data download form. Area cropping is only available for 'time variant variables' (not for time invariant data, the return files for these data will cover the entire domain. See: Auxiliary data)
  • In order to avoid interpolation (which would cause incorrect river discharge values), the EWDS will adjust the requested areas to the GloFAS grid automatically. The GloFAS grid includes points with coordinate values ending as .x25 or .x75 for v4.0, and as .x5 for earlier versions. The adjustment by the EWDS means the retrieved area may be slightly larger larger than the one requested.


Please see the GloFAS known issues for more information, and an example of how the incorrect negative longitude values can be corrected


  • At the bottom of the page you are required to accept the 'terms of use' before you download a dataset. (Note: To accept licences and access data in EWDS you will need an ECMWF account).

  • You will then see a button labelled 'Submit Form', click to download your data selection
  • When you submit the form, a page will appear with the list of your downloads and their associated details including submission date, duration of download, size and status.