Tracing Tornadoes Through Time: Enhancing Tornado Climatology in Romania with Historical Data and Modern Analysis

Tornadoes are violent natural hazards that can cause significant damage and human casualties. Due to their severe and localized impact, they are considered among the most significant small-scale weather phenomena. In this study, we are expanding the existing Romanian tornado database by meticulously documenting additional tornadic events found in historical sources. Thus, we have conducted searches in recently available digital newspaper archives for tornado reports. The search yielded records dating as far back as the late nineteenth century, with the earliest events recorded in 1880. To the existing 199 tornadoes from the Romanian tornado database within the European Severe Weather Database (ESWD), we have added another 46 verified events.  The archival research conducted in this study has uncovered evidence of previously undocumented deadly tornadoes, consequently raising the number of deadly tornadoes in Romania from four to seven.

These 245 tornadoes reported between 1634 and 2024 were then used to construct an enhanced climatology of tornadoes in Romania. Spatial analysis of the updated database indicates a higher frequency of reports from northeastern and southeastern Romania. Temporally, most tornadoes (70%) occur during the warm season (May–July), with a peak in the early afternoon (47%, between 14:00 and 16:00 UTC).

To investigate the environmental conditions associated with tornado occurrence, we analysed a subset of post-1990 cases, up to 2024, using ERA5 reanalysis data. Only tornadoes with time accuracy better than or equal to one hour were included. The comprehensive analysis of tornado records spanning over three centuries and the inclusion of newly documented events significantly contribute to our understanding of tornado climatology in Romania.

This study not only enhances our knowledge of tornadic events in the region but also provides valuable insights into the environmental conditions conducive to tornado formation, thereby improving tornado forecasting and mitigation strategies. The results suggest that many Romanian tornadoes form in high-shear, low-CAPE (HSLC) environments, consistent with findings from other parts of Europe.