This work takes as its reference the guidelines from the Working Table on Resilience established by ARERA. The said guidelines highlight the marked increase in long-term power outages over the last 20 years, mainly due to particularly violent and extended weather events. MERIDA is the reference meteorological reanalysis at a national level for reconstructing main atmospheric threats and estimating return times. It allows you to feed network vulnerability models that have as their inputs the expected values or likelihood of occurrence of a certain meteorological event with increasing return times, typically up to 50 years. The methodology adopted involves the modelling reconstruction of the main meteorological variables with an hourly temporal resolution and on a regular grid of 4 km * 4 km, appropriately thickened up to 1 km * 1 km in some specific cases requested by electricity utilities, such as for the threat of strong winds associated with deep depression circulations. Subsequently, for each threat it is possible to calculate the return time based on the theory of extremes, also known as Extreme Value Analysis. For cloudbursts associated with flash-flooding with flooding of secondary cabinets, the results identified the most vulnerable areas of the Italian territory. For the wet-snow phenomenon, it was possible to further refine the modelling for the reconstruction of sleeves on conductors. The results lay the foundations for the update of the NNA 50341-2-13 national standard, which requires the estimation of sleeve thicknesses for a 50-year return period, differentiated by climatologically similar areas. The analysis of the frequency and intensity of summer heat waves highlighted that these events have become increasingly extended, prolonged and capable of disrupting the distribution network. The soil model reconstruction was conducted with the MERIDA OI input data. The foundations have been laid for the modelling definition of MERIDA HRES (High-resolution for Renewable Energy Sources) which will provide better estimates of the intensity of wind and solar radiation. MERIDA was finally published on the RSE portal, from which it is possible to download numerous surface, atmospheric and soil meteorological variables.