Comparison of thunderstorm days in Poland based on SYNOP reports and PERUN lightning detection system

Abstract

The research presents a comparison between two methods which are used to identify days on which there are thunderstorms (TDs) in Poland. SYNOP and PERUN lightning network data from the Institute of Meteorology and Water Management (IMGW-PIB) for the period 2002–2020 were used to determine and compare the changes in the number of TDs. To determine the number of TDs using the PERUN data, an appropriate method needed to be created which would allow for the closest possible reference to human perception in relation to lightning. A buffer with a radius of 15 km was used, and TDs were counted when there was at least one flash within the buffer circle. Measurements performed by observers are sometimes not homogeneous and are prone to errors, and thus underestimate the actual number of TDs. As a result of the analysis, the average number of TDs in Poland was found to be 26 (SYNOP) and 30 (PERUN) per year.