A process-based anatomy of Mediterranean cyclones: from baroclinic lows to tropical-like systems

Abstract. In this study, we address the question of atmospheric processes that turn Mediterranean cyclones into severe storms. Our approach applies online potential vorticity (PV) budget diagnostics and piecewise PV inversion to WRF model simulations mature stage 100 intense cyclones. We quantify relative contributions different cyclone development therefore deliver, for first time, a comprehensive insight variety cyclonic systems develop in from perspective dynamics. particular, show all are systematically influenced by two main anomalies: major anomaly upper troposphere, related baroclinic forcing development, minor lower diabatic momentum wind. Among processes, latent heat is shown act as source (reinforcing cyclones), being partly balanced sinks temperature diffusion radiative cooling (weakening cyclones). Momentum have an ambiguous feedback, able reinforce weaken while certain cases playing important role development. Piecewise shows most due combined effect both forcing, i.e. anomalies. However, stronger less found processes. Several pairs exemplary used illustrate cyclones: (i) where contribute development; (ii) mainly developed latent-heat release; (iii) developing wake Alps; (iv) unusual cases, one dominates other presenting dual-surface pressure centre. Finally, focus on 10 medicane (i.e. tropical-like contrast their tropical counterparts – but accordance with medicanes under influence discussion medicane-driving highlight need physical definition these systems.