Modern weather forecasting relies on increasingly sophisticated numerical tools, capable of representing atmospheric processes across multiple scales. At the core of this development lies the joint work of scientific communities and meteorological services which, through international cooperation networks, combine expertise and resources to improve the ability to describe and forecast weather and climate phenomena.
The COSMO Consortium, established in 1998 to develop an innovative atmospheric model capable of accurately describing small-scale weather phenomena, represents one of the most significant examples of such collaboration; a scientific infrastructure in which the CIMA Research Foundation, recognized as the Italian Meteorological Entity and working in close synergy with the Italian Civil Protection Department, contributes along crucial lines of research: from urban parameterization to observational data quality control, up to the coordination of updates for the ICON model.
The annual General Meeting of the Consortium is taking place in Basel from 1 to 5 September. This appointment marks each year a point of convergence between research, meteorological services, and institutions, where project results are presented, model evolutions discussed, and future priorities defined.
From COSMO to ICON: continuity and innovation
The COSMO numerical model, created in 1998, was for more than twenty years a benchmark for limited-area atmospheric modeling, used by national meteorological services in several countries both for daily forecasts and for research. Its strength lay in the ability to describe local phenomena with high detail.
Since 2019, however, development has focused on ICON, the new model now operational in multiple countries, which definitively replaced COSMO after its last release in 2021. ICON introduces a more flexible and scalable approach, enabling more consistent and realistic simulations, both in operational forecasting and in climate research.
As a member of the consortium, the CIMA Research Foundation contributes to this methodological transition. As Massimo Milelli, Head of the Meteorology and Climate Department, points out: “ICON is not a simple update of COSMO. It is a new model that makes it possible to address complex atmospheric processes with more robust tools, opening the way to new applications in weather and climate studies.”
Image courtesy of DWD
Urban parameterization: representing the complexity of cities
One of the most relevant scientific challenges concerns the representation of physical processes in urban environments. Cities, due to their concentration of impermeable surfaces, infrastructure, and population, are extremely vulnerable to intense meteorological events such as heat waves and sudden heavy rainfall.
“Integrating cities into models means capturing the most direct signals of climate change. Numerical simulations incorporating these schemes provide concrete added value for risk management and urban planning,” explains Milelli.
CIMA Research Foundation is working on the implementation and testing of urban parameterization schemes within ICON. The goal is to integrate such schemes into the model’s operational version, so as to better represent the specific physical processes of urban environments.
Observational data and quality control systems
The reliability of a model depends on the quality of the observations that feed it. The growing availability of data from regional and national networks entails a dual aspect: a scientific opportunity, but also a challenge in terms of management. Differences in metadata, measurement heterogeneity, and network inconsistencies require advanced systems for observational data quality control.
Researchers at the CIMA Research Foundation contribute to the development of an advanced system to validate precipitation, temperature, and humidity data, producing consistent fields usable for the verification and validation of simulations. This work is a crucial step in improving the performance of the ICON model and strengthening its predictive capacity.
Technical coordination and future perspectives
Within the consortium, the CIMA Research Foundation has also taken on the coordination of Working Group 6, responsible for essential cross-cutting aspects: from technical documentation to verification and testing of new model versions, from user support (both internal and external) to maintenance of the consortium’s website.
As Milelli explains: “Coordinating means knowing how to listen and integrate different perspectives. Only in this way can the model grow as a shared scientific infrastructure, capable of responding to the needs of research and operational applications.” This group not only carries out management activities, but also defines strategic guidelines for medium- and long-term planning, helping to orient the future development of ICON.
An international network
The value of the COSMO Consortium also lies in its composition: a network bringing together national meteorological services such as Deutscher Wetterdienst (DWD, Germany), MeteoSwiss (MCH, Switzerland), the Meteorological Service of the Italian Air Force (ITAF Met, Italy), the Hellenic National Meteorological Service (HNMS, Greece), the Institute of Meteorology and Water Management (IMGW, Poland), the National Meteorological Administration (NMA, Romania), the Israel Meteorological Service (IMS, Israel), and the Federal Service for Hydrometeorology and Environmental Monitoring of Russia (RHM, suspended since 2022).
Alongside these national meteorological services, the Consortium also includes regional institutions and civil and military research centers from member countries, such as the Euro-Mediterranean Center on Climate Change (CMCC), the Center of Excellence for Remote Sensing Techniques and Severe Weather Forecasts (CETEMPS), the Italian Aerospace Research Center (CIRA), ItaliaMeteo, the Regional Agency for Prevention, Environment and Energy of Emilia-Romagna (ARPAE), the Regional Environmental Protection Agency of Piedmont (ARPA Piemonte), and the CIMA Research Foundation.
This community demonstrates how the science of weather forecasting is a collective construction, the result of cooperation and continuous exchange.
In an era in which climate change makes extreme events increasingly frequent and intense, numerical modeling becomes a crucial tool not only for research but also for operational applications in support of society. The strength of the consortium lies precisely in its ability to integrate diverse knowledge into a common scientific heritage, capable of producing more reliable forecasts and guiding informed choices for the future.