Recommended citation: Pérez-Alarcón, A., Sori, R, El-Sehwagy, A., Trigo, R. M.,Nieto, R., Gimeno, L., Salah, Z., Stojanovic, M. (2025). Lagrangian identification of moisture sources for precipitation in severe medicanes: The cases of Ianos, Apollo, and Daniel. MedGU Annual Meeting. Athens, Grece, 10-12 November 2025.

Abstract

The Mediterranean Sea (MS) experiences frequent cyclogenesis throughout the year, producing cyclones with both tropical and extratropical characteristics, often referred to as medicanes. Although less intense and smaller than their tropical counterparts, medicanes are highly hazardous events in the Mediterranean region. While numerous studies have focused on understanding their development, the origin of the precipitation associated with them has been less explored. Therefore, this study examined the moisture sources for precipitation associated with three severe medicanes: Ianos (September 2020), Apollo (October 2021), and Daniel (September 2023). To achieve this goal, cyclone tracks were obtained using the Cyclone Tracking framework (CyTRACK), and precipitation origin was assessed by applying a Lagrangian bias-corrected moisture source approach. Air parcel trajectories were extracted from the global outputs of the FLEXPART model. Results confirm that these three medicanes produced significant accumulated precipitation along their tracks, with noticeable impacts over Greece and parts of North Africa, particularly over coastal regions of Tunisia and Libya. Based on the Lagrangian analysis, the moisture for each medicane’s precipitation primarily originated from the central and eastern MS, albeit with some differences. Ianos primarily gained moisture from the Ionian and Aegean Seas, with minor contributions from remote sources in the Black Sea. Apollo was mainly fueled by moisture from the central MS and received notable terrestrial moisture contributions from the coastal regions of North Africa. Meanwhile, Daniel’s highest moisture uptake occurred over the Ionian Sea, which was critical to its extreme rainfall over Libya, followed by moisture contributions from the Balkan Peninsula. Furthermore, the area-averaged moisture uptake was relatively uniform across cases, ranging from 1.82 to 2.17 mm/6h, while the mean water vapour residence time in the atmosphere varied from 2.7 to 3.6 days. In summary, our findings enhance the understanding of medicanes-related precipitation and confirm that specific moisture source regions are highly dependent on the storm’s track, evolution, and large-scale moisture transport patterns. A climatological study is required to generalise these results.