The kinematic and thermodynamic environment during cloud-to-ground lightning occurrence in Poland

This study identifies convective and kinematic parameters that positively influence elevated values of cloud-to-ground lightning flashes (CGs) in Poland.The analysis used data from the PERUN lightning detection and location system from IMGW-PIB and reanalyses of the ERA5 model from ECMWF for the period 2002-2020.In addition, a spatial-temporal distribution analysis was carried out for the period 1940-2022, covering the key parameters necessary for the appearance of convection.Results showed that thunderstorms most often occur in the summer, but also that there are increasingly favorable conditions for the appearance of organized multicellular systems in the spring.CG flashes most often form in a most-unstable convective available potential energy (MU CAPE) environment of about 1300 J/kg along with vertical wind shear (0-6 km AGL bulk wind shear) of 13-14 m/s.Using the WMAXSHEAR parameter, it was possible to conclude that overlapping CAPE and DLS values of about 500 m 2 /s 2 imply increased electrical activity.At the same time, a high correlation with the Hail Size Index (HSI) parameter implies a positive relationship between the occurrence of hailstorms and an increased number of CGs generated in the case of supercells.The research also found a gradual increase in air temperature, MU CAPE, MU Mixing Ratio and the MU WMAXSHEAR parameter for the area under study.