Nowcasting severe storms using full-constellation Meteosat Third Generation satellite data

When complete in 2026, the full operational Meteosat Third Generation constellation will consist of three satellites: two imaging and one sounding satellite. Together, these data will provide near real time, 3D/4D view of the thermodynamic structure of the atmosphere over Europe and Africa.

The first imager satellite, MTG-I1, launched in December 2022, is operational since 4 December 2024 under the name Meteosat-12. It provides new, more precise and more frequent data to assist monitoring and nowcasting of severe storms that result in often significant and increasing wind, hail, rainfall and lightning hazards. A combination of two instruments onboard, a Flexible Combined Imager (FCI), with its high-resolution spectral imagery, and a Lightning Imager (LI), continuously monitoring the optical emissions of lightning from space, supports forecasters in one of their greatest challenges – providing timely and accurate forecasts of rapidly developing, high impact weather events.

FCI instrument on the MTG-I satellites is the successor of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on the Meteosat Second Generation satellites. Compared to SEVIRI’s 12 spectral channels, FCI has 16 channels, a spatial resolution of 1–2 km delivering a full image of Earth every 10 minutes, and higher radiometric resolution and signal-to-noise ratio. In addition, in four spectral channels, it provides data at even higher resolution (0.5-1 km), and with the addition of the second imager satellite in 2026, observations over Europe will be available every 2.5 minutes.

The first months of operations have demonstrated the added value of FCI and LI in forecasting, such as: more accurate identification of the most intense updrafts in convective cells, more precise imaging of cloud top features, especially glaciation and presence of small ice particles, mapping of moisture content and many more.

The InfraRed Sounder on the MTG-S1 satellite will provide vertical profiles of atmospheric temperature and humidity, offering a 3D/4D view of the atmosphere. The lowest uncertainties to be expected from these profiles, available every 6-7 km and 30min over Europe, are in the order of 1K for temperature and 5-20% for specific humidity, in cloud-free conditions and depending on the vertical level.

Altogether, data from the MTG constellation offer a new and unique source of imaging and sounding information for meteorologists on a wide range of parameters, including cloud characteristics, atmospheric temperature, and lightning frequency, and feeding into regional numerical weather prediction models, used for nowcasting and very short-range forecasting, ultimately supporting better warnings and improved public safety.