A derecho-like event in the southern part of Romania: 20th of July 2011

Derecho storms are high-intensity convective wind events that often cause deaths and significant damage over large areas. 

On the 20th of July 2011, a convective system that presented derecho characteristics formed in Bulgaria and crossed over several counties in southern Romania. Strong storms were present in the largest part of Romania and were associated partially with a cold front and sustained by a rapid southern flow at 500 and 300 hPa. Analysis of the radar data revealed the presence of multiple supercells and bow echoes, reflectivities above 60 dBZ and wind gusts which reached over 25 m/s over a distance of 300 km. Two main storms were identified. One of these passed just 15 km away from the capital Bucharest, causing massive damage in the southern part of Dambovita county. The highest wind gust recorded in Romania peaked 34 m/s at Roșiorii de Vede but in Bulgaria gusts over 40 m/s were measured. Significant damage also occurred in Transylvania, with many winds gusts over 25 m/s.  

The results aim to support the improvement of the early warning activities related to extreme windstorm events, very likely to impact Romania in the next decades, within the climate-changing context. At the same time, it will continue the documentation of significant windstorms and derecho events in Romania.

This work has been financed within project „Dezvoltarea Centrului de Competență pentru Adaptarea Comunităților Locale la Schimbările Climatice prin parteneriate de tip public-privat în domeniul CDI” cod 3/16.11.2022 finanțat prin Planul Național de Redresare și Reziliență Apel nr. PNRR-III-C9-2022 – I5"