Joan Bech1, Ramón Pascual2, Tomeu Rigo1, Nicolau Pineda1, J.M. López2, Joan Arús2, Miquel Gayà3
1Servei Meteorològic de Catalunya, Barcelona, Spain
2Instituto Nacional de Meteorología, CMT Catalunya, Barcelona, Spain
3Instituto Nacional de Meteorología, CMT Illes Balears, Palma de Mallorca, Spain
Tóm tắt
Abstract. This paper presents an observational study of the tornado outbreak that took place on the 7 September 2005 in the Llobregat delta river, affecting a densely populated and urbanised area and the Barcelona International airport (NE Spain). The site survey confirmed at least five short-lived tornadoes. Four of them were weak (F0, F1) and the other one was significant (F2 on the Fujita scale). They started mostly as waterspouts and moved later inland causing extensive damage estimated in 9 million Euros, three injured people but fortunately no fatalities. Large scale forcing was provided by upper level diffluence and low level warm air advection. Satellite and weather radar images revealed the development of the cells that spawned the waterspouts along a mesoscale convergence line in a highly sheared and relatively low buoyant environment. Further analysis indicated characteristics that could be attributed indistinctively to non-supercell or to mini-supercell thunderstorms.
