The following is a description of the upcoming latest operational release of EFAS (v5.4), which was launched on 12 March 2025 with the 12:00UTC forecasts. For an overview of other EFAS releases, please see: EFAS versioning system

Summary

EFAS v5.4 introduces several minor changes to the system, including:

  • Upgraded seasonal and sub-seasonal products, including:
  • The EFAS medium-range forecast skill layer has been updated in two key ways:
    • Expanded Reforecast Coverage: In EFAS v5.0, the forecast skill layer was initially calculated using only the reforecasts for April, May, and June, which were the months available at the time of release. The forecast skill layer in EFAS v5.4 has now been recalculated using a complete set of reforecasts, covering the entire year. For details see: EFAS forecast skill product and EFAS forecast skill score
    • Expanded Reporting Point Network: The forecast skill calculation now includes all reporting points, incorporating the 355 new stations introduced in EFAS v5.3.
  • New radar-based urban flash flood experimental products, updated every hour, available on EFAS-IS ()
  • New Static Layer - Flood inundation scenarios
    • Displays the modelled flood inundation extents associated with return period scenarios of 10, 50, 100 and 500 years (10%, 2%, 1% and 0.2% annual exceedance probability respectively)
  • Update on Hydrological Post-processed (PP) products
    • A banner in the ReportingPoints pop-up window appears when the ensemble forecast mean exceeds either the 5th percentile or the maximum simulated value in the calibration range. This is to highlight the fact that the EFAS post-processed hydrographs are expected to be less accurate at these extreme magnitudes.
  • Revamp of the EFAS Feedback page

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

Technical details

Pre-release date (available on stage platform)

2024-03-05

Release date

2025-03-12 (expected)

In test suite

n/a

EFAS internal number

20
Archiving of data

ECFS, MARS, CDS 

Reference climatology (for thresholds/ anomalies)1992-01-01 to 2022-12-31
EFAS Historical1992-01-01 to near present
Reforecasts

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Horizontal projectionEPSG4326
Horizontal resolution0.01667 x 0.01667°
Temporal resolution6-hourly