The World Meteorological Organization (WMO) has awarded its highest honour, the 71st International Meteorological Organization (IMO) Prize, to Dr. Florence Rabier of France for her transformative contributions to numerical weather prediction. Often described as the Nobel Prize of meteorology, the award recognises her pioneering work in satellite data assimilation that dramatically improved the accuracy of global weather forecasts. The prize carries a cash award of 10,000 Swiss Francs (CHF) along with a gold medal and a parchment scroll.
Who Is Dr. Florence Rabier?
Dr. Florence Rabier, born in 1964, is a French meteorologist and one of the world’s leading experts in numerical weather prediction (NWP). She served as the Director-General of the European Centre for Medium-Range Weather Forecasts (ECMWF) from 2016 to 2025, leading the organisation through a period of major scientific and technological transformation. She currently serves as a Non-Executive Director of the UK Met Office.
The 4D-Var Breakthrough
Rabier is best known within the meteorological community for her key role in implementing the four-dimensional variational data assimilation (4D-Var) method in 1997, a world first. This technique allows weather prediction models to optimally combine vast amounts of satellite observations with physical models of the atmosphere, producing far more accurate initial conditions for forecasts. Her work on assimilating satellite data marked a turning point in global forecasting, particularly by significantly reducing the forecast accuracy gap between the Northern and Southern Hemispheres.
Leading ECMWF: AI and Open Data
During her tenure as Director-General, Rabier spearheaded the large-scale integration of artificial intelligence into weather forecasting systems, complementing traditional physics-based models. This shift improved prediction accuracy while reducing computational costs and making forecasting capabilities more accessible worldwide.
She also led a major transformation by introducing an open data policy at ECMWF, aligned with the WMO Unified Data Policy. This increased global use of ECMWF data, supported operational weather services, and fostered innovation across the meteorological community. Under her leadership, ECMWF strengthened its role as a scientific pillar of key European programmes including Copernicus, the European Union’s Earth observation programme, and initiated involvement in projects like Destination Earth (a digital twin of the Earth) and SEWA (early warning systems in Africa).
The IMO Prize: Meteorology’s Highest Honour
The IMO Prize is named after the International Meteorological Organization (IMO), the non-governmental body founded in 1873 that preceded and later evolved into the WMO. The prize was established in 1955 and has been awarded annually since 1956 to individuals who have made exceptional contributions to meteorology, climatology, hydrology, and related sciences.
The award consists of a 14-carat gold medal measuring 57 mm in diameter, a parchment scroll, and a monetary grant of 10,000 Swiss Francs. The medal bears the Latin inscription “Pro singulari erga scientiam meteorologicam merito” (for outstanding work on the science of meteorology). It is presented by the WMO Executive Council.
Notable Previous Laureates
Over its seven-decade history, the IMO Prize has been awarded to some of the most influential figures in atmospheric science:
| Year | Laureate | Country | Known For |
|---|---|---|---|
| 2025 | Prof. Xu Jianmin | China | Architect of China’s Fengyun meteorological satellite programme |
| 2024 | Prof. Gerhard Adrian | Germany | Former WMO President, leadership in global meteorological cooperation |
| 2023 | Prof. Timothy Palmer | UK | Pioneer of ensemble weather forecasting |
| 2000 | Prof. Edward Norton Lorenz | USA | Chaos theory and the “butterfly effect” in weather |
| 1961 | Prof. K.R. Ramanathan | India | Pioneering contributions to tropical meteorology |
Indian meteorologists who have received the prize include K.R. Ramanathan (1961) and later Pisharoth Rama Pisharoty (1989), both recognised for their foundational work in atmospheric science.
The World Meteorological Organization
The World Meteorological Organization (WMO) is a specialised agency of the United Nations responsible for promoting international cooperation in atmospheric science, climatology, hydrology, and geophysics. Its origins trace back to the International Meteorological Organization (IMO), founded in 1873 to facilitate the exchange of weather data across national borders.
| Aspect | Details |
|---|---|
| Established | 23 March 1950 (WMO Convention entered into force) |
| Became UN specialised agency | 1951 |
| Headquarters | Geneva, Switzerland |
| Members | 193 countries and territories |
| Governing body | World Meteorological Congress (meets every 4 years) |
| Current Secretary-General | Prof. Celeste Saulo (Argentina, since 2024) |
| Current President | Dr. Abdulla Al Mandous (UAE) |
The WMO coordinates the work of National Meteorological and Hydrological Services (NMHSs) worldwide and sets standards for the free and unrestricted exchange of weather, climate, and water data. It leads global initiatives such as Early Warnings for All and the Global Greenhouse Gas Watch.
Significance of the Award
The IMO Prize being awarded to Dr. Rabier holds particular significance for several reasons. Her pioneering work on 4D-Var data assimilation directly improved the quality of weather forecasts used by billions of people daily. The integration of AI into weather forecasting, which she championed at ECMWF, represents a paradigm shift in how predictions are made, moving beyond purely physics-based models to hybrid systems that combine physical understanding with machine learning.
Her leadership in establishing an open data policy at ECMWF has democratised access to high-quality weather data, enabling developing countries and smaller meteorological services to improve their forecasting capabilities. This aligns closely with the WMO Unified Data Policy, which promotes free and unrestricted access to meteorological data globally.
Rabier will formally receive the IMO Prize and deliver the prize lecture during the World Meteorological Congress in 2027.
Key Takeaways
- The WMO awarded the 71st IMO Prize to Dr. Florence Rabier of France, recognising her pioneering contributions to numerical weather prediction and satellite data assimilation.
- Dr. Rabier served as Director-General of ECMWF from 2016 to 2025, where she integrated AI into weather forecasting and introduced an open data policy.
- The IMO Prize, established in 1955, is the highest honour in meteorology, often called the Nobel Prize of the field, and carries a cash award of 10,000 Swiss Francs.
- The prize is named after the International Meteorological Organization (IMO), founded in 1873, which was the predecessor of the WMO.
- The WMO is a UN specialised agency headquartered in Geneva, Switzerland, with 193 member states, and was established on 23 March 1950.
- Indian recipients of the IMO Prize include K.R. Ramanathan (1961) and Pisharoth Rama Pisharoty (1989).
