Preliminary reflectivity analysis of severe convective events in in the proximity of Goczałkowice-Zdrój

Abstract

At the beginning of 2018, the X-band radar in Goczałkowice-Zdrój (southern Poland) was launched. The scanning area corresponds with the scanning area of the POLRAD C-band radar system operated by the Polish Institute of Meteorology and Water Management. New opportunities were created for imaging phenomena by comparing some reflectivity features from C-Band radar and X-Band local weather radar. Moreover, some of the signatures located in the lower troposphere can be better documented by local X-Band radar. Firstly, reports from the ESWD (European Severe Weather Database) have been thoroughly analysed. All severe weather reports in the proximity of Goczałkowice-Zdrój (100-km radius) were gathered into one-storm events. Then the reflectivity from both radars was analysed to determine which reflectivity patterns occurred and when. X-band radars are known from the more intensive attenuation of the radar beam by the scatterers located closer to the radar, thus it is essential to compare capabilities of these two different radar systems. It was found that the average reflectivity for all convective incidents is higher when using POLRAD C-band radar data. In some events it was possible to find some spatial reflectivity signatures. We also discuss other reflectivity signatures previously described in the literature. Taking into account stronger Goczałkowice-Zdrój X-band radar attenuation, we suggest that some of these should be reviewed by reduction of the reflectivity thresholds.