The effect of the boundary conditions on the simulation of the 4 November 1966 storm over Italy

摘要

This study analyses the extreme event which took place on 4 November 1966,when a storm produced intense and persistent precipitation over northern andcentral Italy and an extreme surge in the northern Adriatic Sea, causingcasualties and huge damages. Numerical simulations with a regionalatmospheric model have been performed to reconstruct the phenomenology of theevent. Results have been compared with observations. This study shows thatthe choice of the global fields for initial and boundary conditions iscrucial for the quality of the reconstruction. The simulation is reasonablyaccurate if they are extracted from the NCEP re-analysis, while it is notsatisfactory if ERA-40 data are used, though fields have a higher resolutionin the ERA-40 than in the NCEP set of data. The internal physics of the modelplays a smaller role in the reproduction of the dynamics of the event.