Differential reflectivity columns and hail: Linking C‐band radar‐based estimated column characteristics to crowdsourced hail observations in Switzerland

Differential reflectivity columns () have been shown to provide information about a storm's updraft intensity and size. The updraft's characteristics, in turn, influence a severe storm's propensity to produce hail and the size of said hail. Consequently, there is the potential to use for the detection and sizing of hail. In this observational study, we investigate the characteristics of (volume, height, area, maximum within) detected automatically using an operational C‐band radar network in Switzerland and relate them to hail on the ground using 173,000 crowdsourced hail reports collected over a period of 3.5 years. We implement an adapted version of an established detection algorithm on a three‐dimensional composite of data derived from five Swiss weather radars. The composite, in combination with the dense network of radars located at differing altitudes up to 3000 m above sea level, helps to counteract the effects of the complex topography of the study region. The alpine region presents visibility and data‐quality challenges, which are especially crucial for measuring . Our analysis finds present in most hail‐producing storms, with higher frequencies in storms producing severe hail. Further, when looking at lifetime maximum values, we find significant differences in various characteristics between hail‐producing and non‐hail‐producing storms. We also attempt to determine thresholds to differentiate between storm types. The temporal evolution of proves challenging to investigate due to their intermittent nature. Nevertheless, the peak values of characteristics are most often measured 5–10 min before the first hail reports on the ground, highlighting the potential for to be used in warning applications.