Page History

The following is a description of the latest operational release of EFAS (v5.23), which was launched on 13 August  12 November 2024. For an overview of other EFAS releases, please see: EFAS versioning system. 

Summary

EFAS v5.2 3 introduces several minor changes to the system, including:

• Revised Notification criteria for Formal and Informal notifications: 
  
  • Optimised criteria for the issue of Formal and Informal notifications are based on a new methodology for the computation of the total probability of exceedance of the 5 yr RP threshold of the grand ensemble encompassing all Numerical Weather Predictions.
    
  • Improved definition of the area of validity of Formal and Informal notifications.
  • Revised layers in the EFAS Map Viewer: 
    • (a)  5-year exceedance < 48 h and 5-year exceedance > 48 h replace the layers Flood Probability < 48 h and Flood Probability > 48 h, respectively;
    • (b) Flood probability layer replaces the former Flood probability persistence layer; 
    • (c) Reporting Points pop-up window has been updated to show total probability and grand ensemble.
  • Improved EFAS notifications email to include a link to a preview feature in the Notifications Archive.

• Stations metadata have been updated to better align them with the hydrological data collected by EHDCC.
• Updated flood protection levels layer using new information in EU member states
• Updated Major Rivers layer derived from 4 different datasets: FAO AQUASTAT, EU hydro, Natural Earth, and GRDC; improved visualisation of river network and river names.
  
• Updated documentation on FTP Access

• New calibration of Hydrological Post-Processing (HPP) stations: A total of 1948 stations were calibrated at 6-hourly time steps and a further 228 were calibrated at daily time steps based on EFAS v5 hydrological reanalysis (water balance) and observations up to 15 October 2024. This includes 355 new post-processed stations (274 stations at 6-hourly and 81 stations at daily). Results of the evaluation of all stations for this calibration can be viewed here.
• Update to fixed reporting points: A total of 865 new stations were added as reporting points, bringing the total number of reporting points to 4421.
• Medium-range reforecasts
  • Change in the reforecast dates now released every month on the 1/5/9/13/17/21/25/29 (excluding 29 February) and not every Monday and Thursday as previously done. This may have an implication for users using CEMS-Flood reforecast data in their downstream application as the scheduling of reforecast date will change. See Implementation of IFS Cycle 49r1 for more details.
  • Temporary freeze of medium-range reforecasts available from the EWDS, with no update of the dataset from EFAS v5.3 release date. If you require access to the reforecast data, please get in touch with us via the ECMWF Support Portalusing the title 'Access to EFAS Reforecast Data' when creating the ticket. Information on how to raise a ticket in our support portal is availablehere.

This upgrade of EFAS has no impact on the EFAS modelling results.

Technical details