Global flood forecasts now run on an AI weather model. What changes for users?
GloFAS v4.4 moved its operational forecasts onto ECMWF’s AIFS. The flood model downstream is the same; the weather it is fed is not.
- GloFAS v4.4, released in September 2025, runs operational global flood forecasting with ECMWF’s AIFS model.
- It covers short-, medium- and long-range forecasts, plus satellite-based flood detection.
- For users the interface is unchanged; what matters is how the forecasts verify over the next seasons.
The Global Flood Awareness System is the forecast many national agencies and humanitarian teams check first when a large river starts to rise. Its v4.4 release, in September 2025, made a quiet but significant change: the operational system now runs with ECMWF’s AIFS model.
Two models, one chain
A flood forecast is a chain. A weather model predicts rain and temperature; a hydrological model turns that into river flow. Changing the first link changes everything downstream, even when the river model itself is untouched.
That is why the change deserves attention from anyone who uses GloFAS thresholds operationally. Return-period alerts calibrated on one weather model may behave differently when fed by another.