Winter windstorms rank as one of Europe's deadliest and most damaging natural disasters. To model the impacts of these windstorms, surface wind data can be incorporated into climate risk models to derive estimates of natural hazard-related impacts on natural or socio-economic systems. In CLIMADA, risk from a natural hazard can be modelled as the convolution between three components - hazard, exposure, and vulnerability.  The vulnerability component links the hazard and exposure components to give total impact that can be approximated through functional relationships called vulnerability curves (or impact functions in CLIMADA). Advancing the science of impact estimation from windstorms is imperative for mitigation and management of changing climate risks, and this relies on appropriate calibration of the vulnerability curve. To this end, in this study, we calibrate a popular impact function from Schwierz et al. (2010) using impact data from two types of sources: open-source (EM-DAT/XWS) and proprietary (PERILS). Results indicate substantial differences between the calibrated vulnerability curves and highlight the importance of the type of recorded disaster data used in calibration. Furthermore, for each of the aforementioned calibration cases, we discuss the uncertainties associated with the use of different cost functions and optimization techniques in the calibration process. The study brings forth how data and method choices influence vulnerability curves, helping better understand modelling uncertainty and support the development of more reliable tools for climate risk assessment and adaptation.

How to cite: Mishra, A. N., Messori, G., Riedel, L., Satheesh, A. R., Ramos, A. M., and Pinto, J.: Towards improved assessment of windstorm damage risk through Impact Model calibration, 12th European Conference on Severe Storms, Utrecht, The Netherlands, 17–21 Nov 2025, ECSS2025-326, https://doi.org/10.5194/ecss2025-326, 2025.

It has now been a year since Météo-France forecasters began using MTG data on a daily basis. Four seasons have passed, including a convective season, during which the new MTG products were put to the test and the existing ones were re-evaluated.

The Satellite imagery innovation and outreach department from the Meteorological Satellite Centre has set up a dedicated support program to best support forecasters in getting accustomed to these FCI images, as well as to remind them of the basics of existing products.

Quick guides have been written for all products, training sessions have been conducted, including a specific one-day course on convection. Communication networks have been established to exchange information on best practices. "Satellite expert forecasters" soon provided us numerous insights on the products: interesting use cases, performances, questions about colours, anomalies, etc.

Skills development is still an ongoing two-way process, involving both the provision of theoretical knowledge and the consideration of extensive user feedback. The numerous exchanges within the international community in which the Meteorological Satellite Centre participated also led to the development of consistent and universal satellite image analysis methods, particularly on the subject of convection.

Cloud top features, cloud top temperature, cloud top particle phase and size, inflow with moisture supply, outflow, cloud vertical extension... all these parameters are relevant when it comes to convection, and FCI is able to provide this information very effectively. Not to mention the gain in spatial and temporal resolution.

But satellite products are becoming increasingly numerous and accurate, each with its own specific features. The large amount of information available to forecasters can sometimes be counterproductive. Time can be short during a shift, particularly in high-stakes situations such as severe convection.  It is necessary to select the relevant elements, and keeping in mind the most useful applications of each product will allow forecasters to optimize the analysis and monitoring of weather conditions.

This poster provides an overview of the FCI products best suited to stormy situations, as well as highlighting the most relevant applications of each.

How to cite: Desire, R., Coste, R., and Hernandez, J.-B.: Convection monitoring: recommended FCI products, 12th European Conference on Severe Storms, Utrecht, The Netherlands, 17–21 Nov 2025, ECSS2025-327, https://doi.org/10.5194/ecss2025-327, 2025.

Since September 26, 2024, Météo-France has been producing and making available to forecasters around 50 products derived from FCI and LI data. The newest ones are proving very successful. But popularity does not lie just in novelty.

The Sandwich product, already well known for many years, has become one of the flagship products used by forecasters. It was not distributed with MSG at Météo-France, taking its applications into account was a real eye-opener. The 500 m resolution adds great value, with a significantly increased amount of information when it comes to convective situations.

This product makes it possible to observe cloud top features, with a level of detail never seen before with a geostationary satellite at 0° position. These features can be linked to the occurrence of dangerous phenomena, such as severe gusts or large hail. While cloud top features were already well known to forecasters, partly because they were already visible with MSG, others proved to be more novel, as they had been little or not at all observed until then.

A skills upgrade is underway within the forecasting community, particularly at Météo-France, through MTG training courses. Identifying these storm systems is crucial for forecasters, who can then alert the relevant authorities in real time to the likelihood of severe weather.

Due to Météo-France's territorial presence in several overseas territories and the needs of the armed forces and civil security services, the Sandwich product had to be adapted so that it could remain usable on the entire FCI disk.

In literature, colour usually ranges only account for temperatures up to - 70 °C. The colour does not change beyond this value, which results in a loss of information about the temperature at the top of the coldest clouds. The colour palette has therefore been tuned for such very cold clouds frequently encountered in tropical latitudes, while remaining consistent with experts and community standards.

In addition, a new feature has been implemented: a night-time version, with infrared channel 10.5 taking over the visible channel as the background image. The result is a complete, smooth product, with consistent images between day and night, and a seamless transition between the two. Cloud top features have indeed specific thermal signatures, including at night.

Thus, after extensive consultation with users, a finalized and complete version of the Sandwich product was introduced at Météo-France.

How to cite: Desire, R., Hernandez, J.-B., Mauss, A., and Perier, L.: Météo-France Sandwich product:a version tailored to the needs of all French users, 12th European Conference on Severe Storms, Utrecht, The Netherlands, 17–21 Nov 2025, ECSS2025-328, https://doi.org/10.5194/ecss2025-328, 2025.

99% of atmospheric water is in gaseous form, namely water vapour, mainly concentrated in the lower layers of the atmosphere. This amount of water vapour defines the amount of precipitation that a given area can receive: this is referred to as precipitable water.

Water vapour can be transported over long distances and releases energy as it condenses. It can therefore be considered as the fuel that powers meteorological processes. In situations of intense convection in particular, the severity of storms will depend on this moisture supply.

The water vapour channels typically available with geostationary satellite imagers allow us to assess the amount of water vapour in the upper and even middle troposphere. However, it is precisely in the lower layers that the concentration of water vapour is highest and most relevant to assess for the analysis of moist inflow of storm cells.

A new channel is available with (and only with) the MTG FCI imager: VIS0.9. This channel provides information on vertical water vapour content, particularly in the lower third of the troposphere. Although a signal may also be visible at higher levels, this is the first time that water vapour content can be observed and tracked near the ground, and not just in the upper and middle troposphere. Satellite products have already been developed within the international community, notably the ESSL total moisture composite.

It was during an ESSL testbed that a senior national forecaster at Météo-France discovered this possibility of assessing water vapour in the lower layers and highlighted the need for it. In addition to its obvious contribution to convection, this product may also prove useful in addressing the issue of forest fires by identifying dry air advections.

The Meteorological satellite centre of Météo-France has therefore worked on developing a product that meets these needs, with additional objectives:

• to offer a contrasting colour palette to obtain maximum detail in water vapour content gradients;
• easily identify cloud masses in order to avoid them without using a cloud mask. This product can only be used in clear skies.

This poster presents a preliminary version of the “Météo-France Total Water Vapour Composite” product.

How to cite: Desire, R., Mauss, A., and Hernandez, J.-B.: Météo-France Total Water Vapour composite: precipitable water imagery, 12th European Conference on Severe Storms, Utrecht, The Netherlands, 17–21 Nov 2025, ECSS2025-329, https://doi.org/10.5194/ecss2025-329, 2025.