Environmental Agency of the Republic of Slovenia - Slovenia
The aim of the study is to analyze the case of severe convective storms in Slovenia on 30 May 2001. The damage caused by rain and hail was severe on plants as well as cars and houses since the area of severe rain with hail encompassed the city of Ljubljana. The diameter of hail on the ground exceeded 6 cm, and the return periods of rainstorms, which occurred in some parts of Slovenia, were more than 50 years. The atmosphere was very unstable because of the strong heating of the air at the ground and the advection of cold and moist air in the higher part of the atmosphere as a consequence of the approaching cold front from northwest.
The analysis of temporal and spatial occurrence of convection was made with the aid of satellite pictures, radar data, lightning detection and observed ground station precipitation. The verification of the forecast of the meteorological operational models ECMWF and ALADIN was done for the case study. The forecast of the areas of convective cells and unstable air was particularly verified.
The impact of radiosonde measurements and polar - orbital satellite data on the reliability of very short time forecast was studied.