Severe Weather Events and Sea Level Variability Over the Mediterranean Sea: The WaveForUs Operational Platform

Abstract

The storm surge, i.e. sea-level elevation due to severe atmospheric conditions (strong winds and low pressures), is a major factor of coastal inundation that can induce significant problems over low-land areas. ‘WaveForUs’ is a high-resolution forecasting system for public and emergency use that delivers meteorological and sea-state predictions over the Mediterranean Sea (0.15°). The results of a 2-D hydrodynamic model, that simulates the sea-surface elevation due to the combined effect of atmospheric forcing (pressure and wind) and astronomical tides, are used to estimate the total surge along the coasts. The meteorological model used is the Weather Research and Forecasting model with the Advanced Research dynamic solver. We investigate the relation between extreme surge events and the atmospheric low-pressure systems during two severe weather events that appeared in the 2013–2015 period. Comparisons with the available satellite and in situ observations and gridded analyses show the good performance of the operational system. The morphological changes over a coastal region (e.g. orientation, existence of straits and islands) play an important role on the storm surge variability during a severe atmospheric low-pressure event. The seasonal variation of both weather storms and storm surges during the study period is also under investigation.