Severe Convective Storms and Hail

Atmospheric convection drives many meteorological phenomena that pose significant threats to people and property. This course aims to provide participants with a robust and integrated understanding of convective storms, blending theoretical foundations with practical forecasting techniques, with a particular focus on hailstorms. The program will begin with an overview of moist atmospheric thermodynamics. A key tool in this analysis are the radiosoundings and the respective thermodynamic diagrams, which will be explained to help participants develop a solid understanding of their interpretation. Among the most important outputs derived from radiosoundings are the instability indices; the course will delve into their climatology, emphasizing their spatial and temporal variability across complex terrain and different global regions. The course will then transition into the dynamic aspects of convection. Different convective modes will be examined, each with its typical life cycle and associated hazards. Particular attention will be given to how complex terrain influences the evolution of convective systems. Real case studies and idealized model simulations will highlight how orographic features and sea-atmosphere interactions influence storm development and maintenance. Another key focus of the course will be the initiation of convection, exploring various triggering mechanisms such as bores, gravity waves, cold pools, and upslope flows along mountainous terrain. Hailstorms, as one of the most damaging convective weather phenomena, can cause extensive damage to buildings, crops, and vehicles. The course will thoroughly examine hail microphysics, covering the processes of formation, growth, and melting, integrating theoretical knowledge with practical applications. Participants will gain insights into hail measurement and detection focusing on remote sensing techniques. The principles of radar operation will be discussed in detail, especially with regard to dual-polarization. A dedicated part of the course will deal with the ground-impacts from hailstorms and especially with the evaluation of hazards. The hail risk will be assessed through probabilistic models which also have insurance applications. In addition to hail, other convective phenomena such as tornadoes, lightning and heavy convective rainfall will also be examined. This analysis will be conducted using a combined approach that integrates observational data with numerical modeling simulations. Daily weather briefings will provide an operational forecasting component, enabling participants to apply their knowledge to real-time convective scenarios. Finally, the potential impact of global warming on convective weather will also be addressed, taking into account both emerging observational trends and projections from numerical models. The course is intended for graduate and PhD students, post-doctoral and senior researchers, operational weather forecasters and anyone interested in deepening their knowledge of deep atmospheric convection over mid-latitudes.