The following is a description of the upcoming latest operational release of EFAS (v5.34), which was launched on 12 November 2024. For for testing on the EFAS Stage Platform on 5 March 2025. The operational release is expected on 12 March 2025 with the 12:00UTC forecasts. For an overview of other EFAS releases, please see: EFAS versioning system.
Summary
EFAS EFAS v5.3 4 introduces several minor changes to the system, including:
- Upgraded seasonal and sub-seasonal products, including:
- 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.
- Similar methodologies for both seasonal (monthly anomalies) and sub-seasonal (weekly anomalies) products, with now both basin averages and river network information available.
- Expected forecast anomaly and associated uncertainty signal generation based on the anomaly of individual ensemble members against reforecast-based climatological distributions
- Selectable forecast horizon for the river network and basin summary outlook maps
- Pop-up windows showing the evolution of antecedent conditions and forecast anomalies against background climatology with details on forecast probabilities and expected anomalies for selected reporting points
- For details on the products and methodology see: Hydrological Products Overview, EFAS Seasonal Outlook, EFAS Sub-seasonal Outlook, CEMS-flood sub-seasonal and seasonal forecast product generation methodology & EFAS sub-seasonal and seasonal forecasting.
- 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 ()
- Radar-based urban flash flood hazard product highlights 1-km urban grid cells where risk of flash flooding due to intense rainfall over the next 6-hours
- Radar-based precipitation hazard product showing ellipses where intense storm cells could lead to urban flash flood hazards over the next 3 hours
- The products are experimental and not monitored operationally
- 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
- Provides better integration with the existing Notification details page
- Adds two new Feedback related pages:
- List of feedbacks submitted by your partner - https://european-flood.emergency.copernicus.eu/react/feedbacks/partner/
- List of notifications that your partner has not submitted any feedback to - https://european-flood.emergency.copernicus.eu/react/feedbacks/partner/due/
- 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
| 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 Historical | 1992-01-01 to near present |
| Reforecasts | tbc |
| Horizontal projection | EPSG4326 |
| Horizontal resolution | 0.01667 x 0.01667° |
| Temporal resolution | 6-hourly |