Latest operational EFAS release

The following is a description of the latest operational release of EFAS (version 5.5), which was launched on 10 September 2025. For an overview of other EFAS releases, please see: EFAS versioning system. 

Summary

EFAS v5.5 introduces several changes to the system, including:

• Inclusion of ECMWF’s Artificial Intelligence/Integrated Forecasting System (AIFS) model in EFAS. 
  • Documentation about the operational release of ECMWF's AIFS model, including information on versions, is available on this dedicated AIFS webpage.
  • AIFS Single replaces the ECMWF Deterministic (ECMWF Det.) model in the meteorological forcings of EFAS: EFAS Meteorological forecasts
  • AIFS Single replaces the ECMWF Deterministic products in EFAS-IS:
    • in the Hydrological tab, AIFS Single replaces the Det.ECMWF product: Hydrological Products Overview
    • in the Meteorological tab, AIFS Single replaces the Acc. Precip. Det. ECMWF product:  Meteorological Products Overview
    • in the Flood Summary tab, the Reporting Points products have been updated to include the AIFS Single model instead of ECMWF Deterministic: EFAS Reporting Points
• AIFS is now included in the EFAS Hydrological Post-Processed (HPP) forecasts:
  • All post-processed stations have been calibrated using new observations up to 19 August 2025 (1948 6-hourly and 228 daily).
  • Calibration of the post-processing method was evaluated at each successfully calibrated station using the Kling-Gupta Efficiency Score and the Continuous Ranked Probability Score. Results of the evaluation are available on this page: EFAS v5.5 - Hydrological Post-Processing Evaluation
• New naming convention of NWP forcing
  • ECMWF medium-range NWP called IFS ENS, in line with ECMWF's naming convention
  • ECMWF control member called IFS CF (equivalent to deprecated ECMWF HRES forcing)

This upgrade of EFAS changes the reporting point estimation.

Technical details