ABSTRACT. –The 22-27 July 2008 severe weather event – an example of retrograde Mediterranean cyclic flood. The 22-27 July heavy precipitation events that affected the north-eastern part of Romania are described here in terms of meteorological analysis. The Romanian territory is affected by the presence of Mediterranean cyclones transporting moist and warm air from the Mediterranean Sea basin. In certain meteorological conditions, the Mediterranean Lows moving towards eastern Europe get a retrograde movement over the Black Sea and thus contribute to the increased moisture content of the forming convective systems. Retrograded Mediterranean Lows affect primarily the north-eastern part of Romania. Additionally, different mesoscale forcing mechanisms continuously generate convective cells and focus deep convection over a region for several hours, increasing thus the flash flood potential. ECMWF model analysis is used to investigate dynamical forcing and a mesoscale numerical simulation using the ALADIN model is carried out to investigate the mechanism responsible for convection development. Data from conventional weather stations, as well as radar and satellite imagery are used for investigating the role played by different modes of convective system organization in flash flood generation. The aim of this paper is to identify the different mesoscale and synoptic scale processes leading to continuous regeneration of convection in the same area, that leads contributes to heavy rain accumulation in a short period of time in north-eastern part of Romania.
Key words: severe weather event, flash floods, damages