Environments associated with lightning occurrence based on pre- and post-convective rawinsonde measurements in Central Europe

Rawinsonde measurements performed at 14 stations in Central Europe between 2006 and 2018 were evaluated to investigate atmospheric environments that influence the occurrence of lightning. Our primary focus was on the differences between lightning and non-lightning profiles, pre- and post-convective profiles, and increasing lightning flash rates divided into marginal, moderate and severe categories. In total, 137,501 quality-controlled measurements were used in the study, among which 59,323 were associated with non-zero convective available potential energy. A thundeR rawinsonde processing package was used to calculate 326 parameters for each atmospheric profile while their performance was evaluated using a metric of area under curve (AUC). Our results indicate that lifted index (LI) and its effective version (LI_eff) are the most robust predictors of lightning in both warm and cold environments, and can be used in assessing lightning flash rates. Other useful parameters are CAPE in a hail growth zone (CAPE_HGL), cold cloud depth (Cold_layer) and equilibrium level temperature and height (EL_tmp, EL_hgt). A vast majority of thunderstorms formed with CIN in the lowest 4 km of the parcel profile (CIN_4km) larger than -100 J kg^-1. We also found that relative humidity between 1–4 km (RH_14km) played an important role in thunderstorm development in warm environments, while in cold environments lightning was more often accompanied by stronger atmospheric flow, but it did not affect flash rate. Non-lightning but unstable profiles featured barely any instability in the convective cloud layer below -10°C, highlighting the importance of buoyancy in this layer for lightning development.