Modelling the Scales of Hail

On average, the largest registered hailstone per year in Europe has a diameter of about 11cm. Individual hail events can cause losses exceeding one billion Euros. Therefore, the insurance industry is interested in modelling local hail risk. In fact, questions can be as specific as ‘What is the probability that this specific solar panel or roof window gets destroyed by hail within the next year?’

Meteorological modelling on the other hand describes the probability of hail on synoptic scales. Moody’s RMS developed a hierarchy of statistical models downscaling the risk from the large synoptical scale down to individual objects at risk.

I will discuss how the models are designed and calibrated to characterize local risk as well as spatial correlation on various time scales. To make the final model applicable for the insurance industry a thorough validation analysis is performed and results of this validation are shown in this presentation.