Radar-based assessment of hail frequency in Europe Elody Fluck1,*, Michael Kunz1,2, Peter Geissbuehler3, and Stefan P. Ritz3 1Institute of Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany 2Center for Disaster Management and Risk Reduction Technology (CEDIM), Karlsruhe, Germany 3RenaissanceRe Europe AG, Zurich, Switzerland *now at: Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel Correspondence: Elody Fluck (elody.fl
[email protected]) Abstract. In this study we present a unique 10-year climatology of severe convective storm tracks for a larger European area covering Germany, France, Belgium, and Luxembourg. For the period 2005-2014, a high-resolution hail potential composite of 1×1 km2 is produced from two-dimensional reflectivity radar data and lightning data. Individual hailstorm tracks as well as their physical 5 properties, such as radar reflectivity along the tracks, were reconstructed for the entire time period using the Convective Cell Tracking Algorithm (CCTA2D). A sea-to-continent gradient in the number of hail days is found to be present over the whole domain. In addition, the highest number of severe storms is found on the leeward side of low mountain ranges such as the Massif Central in France or the Swabian Jura in Southwest Germany. A latitude shift in the hail peak month is observed between the northern part of Germany 10 where hail occurs most frequently in August, and southern France where the maximum of hail is two months earlier. The longest footprints with high reflectivity values occurred on 9 June 2014 and on 28 July 2013 with lengths reaching up to 500 kilometers.