Characteristics of hail hazard in South Africa based on satellite detection of convective storms

Abstract

Abstract. Accurate estimates of hail risk to fixed and mobile assets such as crops, infrastructure and vehicles are required for both insurance pricing and preventive measures. Here we present an event catalog to describe hail hazard in South Africa guided by 14 years of geostationary satellite observations of convective storms. Overshooting cloud tops have been detected, grouped and tracked to describe the spatio-temporal extent of potential hail events. It is found that hail events concentrate mainly in the southeast of the country, along the Highveld and the eastern slopes. Events are most frequent from mid-November through February and peak in the afternoon, between 13 and 17 UTC. Multivariate stochastic modeling of event properties yields an event catalog spanning 25 000 years, aiming to estimate, in combination with vulnerability and exposure data, hail damage for return periods of 200 years.