Invited Talk

Abstract: Climate science has long relied on simulated and projected events to populate the statistics of climate variables, using models to generate large synthetic populations of events from which the moments of a climate distribution (mean, variance, and especially its tail) can be estimated, precisely because short observational records cannot sample rare extremes with any statistical robustness. This study applies that same strategy to Mediterranean hurricanes, or "Medicanes": rare, high-impact tropical-like cyclones bringing intense rainfall to densely populated coastal regions, for which too few real cases exist to build a reliable climatology. Building on a statistical-deterministic downscaling methodology used for over a decade to translate global climate model output into storm-scale hazard information , from early applications on CMIP3 simulations (Romero and Emanuel 2013) to CMIP5-based projections (Romero and Emanuel 2017) , we generate thousands of synthetic medicane tracks from reanalysis data and global climate models. Coupling these tracks with a physics-based tropical cyclone rainfall algorithm produces spatially and temporally resolved precipitation fields, from which the full statistical distribution of medicane rainfall and its associated return periods , can be estimated, even for magnitudes far beyond anything recorded to date. The approach is validated against reanalysis, satellite, and radar observations, and sensitivity analyses probe how synthetic sample size and algorithmic choices affect the resulting statistics. Under the RCP8.5 scenario, the resulting hazard distribution shifts markedly: 250-year rainfall along the Adriatic coast increases by up to 160 mm, and some 500-year events are projected to exceed 800 mm of total rainfall. By showing how synthetic event generation can be used to populate and characterize the statistics of a rare climate hazard, this work offers a methodological blueprint directly relevant to AI- and data-driven approaches now being developed to model climate extremes for which observations alone will always be insufficient.

Saraceni, M., L. Silvestri, P. Bongioannini Cerlini, R. Romero, and K. Emanuel, 2026: Estimating Medicane Precipitation Hazard. Journal of Climate, in press, https://doi.org/10.1175/JCLI-D-25-0364.1.

Short Bio: Dr. Paolina Bongioannini Cerlini is a researcher at the Department of Physics and Geology, University of Perugia, where her work focuses on atmospheric dynamics, hydrostatic and non-hydrostatic numerical modelling, and the study of moist convection, from mesoscale processes up to the global scale. Alongside her teaching activities, she coordinates a research group and has taken part in and promoted several projects, including RIMU-CLIMA (Integrated Umbrian Meteorological Network and meteo-climatic advisory service in Umbria), funded by the European Commission. She earned her PhD in Physics, Geophysics track, from the University of Bologna, and held a postdoctoral position at MIT with Kerry Emanuel, working on the predictability of convective precipitation. She has collaborated with ECMWF for over twenty years, following its HPC infrastructure and its weather and climate prediction tools (Copernicus) as well as machine learning tools (Anemoi) applied to atmospheric modelling, which she integrates into her research and teaching activities in the field of climate science.