Total lightning for the early warning: Severe weather signatures from the real-time Lightning Mapping Array network in Catalonia

Lightning Mapping Array (LMA) networks detect very-high-frequency (VHF, 60–66 MHz) emissions from lightning channels inside clouds. This enables the mapping of lightning in three dimensions. The use of real-time LMA data has proven beneficial for forecasting and warning about impending severe weather. Beyond the standard analysis of cloud-to-ground lightning information, the ability to visualize 3D total lightning has provided forecasters with greater knowledge of storm-scale processes.

A network of more than 20 LMA stations has been established in Catalonia (northeastern Iberian Peninsula) thanks to a partnership between the Meteorological Service of Catalonia (SMC) and the Technical University of Catalonia (UPC). Since it began real-time operations during the summer of 2023, it has grown to become Europe's largest LMA network.

To complement classic severe weather signatures observed in weather radar (e.g., storm splitting, BWER, TBSS) and in satellite imagery (e.g., overshooting tops, v-shape), we put our focus here on severe weather signatures observed with the LMA network during the thunderstorm seasons of 2023 and 2024 in Catalonia. Indeed, lightning distribution and evolution can portray complementary information in real-time surveillance, adding confidence to the forecaster and therefore reinforcing the decision-making when issuing alerts for imminent severe weather.