ECMWF scientists Tim Hewson and Fatima Pillosu have received the British Royal Meteorological Society’s 2024 Hugh Robert Mill Award for Precipitation Research for their achievements in improving the accuracy of rainfall forecasts, with a focus on extreme events.
The prestigious award, granted annually for original research into the distribution or variation of rainfall or its application to meteorology or a related science, was presented on 4 June at the Royal Meteorological Society (RMetS) Annual General Meeting.
The two ECMWF scientists were recognised for developing the ecPoint methodology, a post-processing technique that advances rainfall predictions for point (rain gauge) scale and that also adjusts reanalysis data to deliver compatible climate-related products.
Tim, who leads a group responsible for real-time forecast performance monitoring at ECMWF and who also leads forecast product development, said: “Our primary goal was to help improve warnings of localised extreme rainfall, a cause of environmental devastation and fatalities.”
Last year, Europe experienced the most widespread flooding since 2013, and 413,000 people were affected by storms and flooding, the 2024 European State of the Climate (ESOTC) report indicates. The report is published by the EU’s Copernicus Climate Change Service (C3S), implemented by ECMWF, and the World Meteorological Organization (WMO).
Forecasts of a possible ‘worst case scenario’, for 12 h rainfall in mm (98th percentile), valid 06–18 UTC on 15 May 2025, when flash floods were reported at locations scattered across Sicily (storm ‘Ines’). The top row shows forecasts from the raw ECMWF ensemble, and the bottom row shows forecasts from the post-processed ecPoint version of this. Forecast lead times are four days in advance (left panels) and one day in advance (right panels). Relative to the raw model, the ecPoint forecasts, in general, are devoid of unjustifiable detail, exhibit higher maxima, and show less jumpiness. These are all desirable properties given that ecPoint also scores much better, globally, against rain gauge observations.
As flooding is becoming increasingly common, tools such as ecPoint are needed to provide more accurate forecasts and reanalyses of extreme rainfall. ecPoint offers more precise predictions by adjusting raw model output according to the local weather situation, which can help agencies with flash flood risk management.
The underpinning calibration also brings fresh insights for model developers into how model errors and rainfall distribution vary according to the ongoing weather situation, an understanding which is one of the central tenets of the Hugh Robert Mill award.
“ECMWF provided the perfect environment, facilitating seamless progression from research to user-oriented products,” said Fatima, a visiting scientist at ECMWF and PhD student at the University of Reading. “Working with the University of Reading was also crucial to explore hydrometeorological applications such as flash flood risk prediction.”
Many hydrometeorological services from our Member and Co-operating States and other countries around the world have given positive feedback about ecPoint outputs, whilst implementing testing, training and operational use for forecasting.
“For us, personally, the fact that ecPoint provides tangible benefits for the wider society, especially in the Global South, strengthens our motivation,” concluded Tim.
Royal Meteorological Society
The Royal Meteorological Society (RMetS) awards information is provided on the RMeTS website.