Severe storms pose significant and increasing hazards to society. EUMETSAT's Meteosat Third Generation (MTG) mission objective is to improve forecasts of weather and severe storms in particular. To reach this goal, a new instrument, i.e., the Lightning Imager (LI), will provide for the first time from a geostationary orbit real-time data over Europe and Africa on the location and intensity of lightning flashes.
In order to prepare for innovative nowcasting applications using novel MTG capabilities, EUMETSAT has granted RMI a three-year fellowship on the subject 'Towards an automated severe weather warning tool based on MTG-LI and Flexible Combined Imager (FCI) data'. During this project the scientific relevance and applicability of a total lightning jump (LJ) algorithm in an automated thunderstorm tracking tool will be explored to aid and improve nowcasting of severe weather.
Nowcasting defines short term forecasts of the weather within the next hours. As a contrast to the extensive numerical weather prediction (NWP) it makes use of recent observations and other information available at the time of initiation. Thunderstorm nowcasting can benefit from real-time geostationary (GEO) lightning observations as the lightning activity indicates the presence of deep convection. Complementing the upcoming MTG-LI instrument, the similar Geostationary Lightning Mapper (GLM) observes lightning over the Americas and adjacent oceans operationally. The research conducted at the RMI in cooperation with EUMETSAT uses modern nowcasting software to detect and track thunderstorms in GEO satellite images (see Figure). The continuous observation of the lightning activity during the life cycle of a thunderstorms can be used in order to identify rapid increases in the storm flash rate, so-called Lightning Jumps (LJs), that in turn promote nowcasting severe weather events and heavy precipitation at the ground.