Use of the European Severe Weather Database to verify satllite-based storm detection or nowcasting

Abstract

Severe thunderstorms constitute a major weather hazard in Europe, with an estimated total damage of € 5-8 billion each year. Yet a pan-European database of severe weather reports in a homogeneous data format has become available only recently: the European Severe Weather Database (ESWD). We demonstrate the large potential of ESWD applications for storm detection and forecast or nowcasting/warning verification purposes. The study of five warm-season severe weather days in Europe from 2007 and 2008 revealed that up to 47% of the ESWD reports were located exactly within the polygons detected by the Cb-TRAM algorithm for three different stages of deep moist convection. The cool-season case study of extratropical cyclone “Emma” on 1 March 2008 showed that low-topped winter thunderstorms can provide a challenge for satellite storm detection and nowcasting adapted to warm-season storms with high, cold cloud tops. However, this case also demonstrated how ESWD reports alone can still be valuable to identify the hazardous regions along the cold front of the cyclone.