The aim of the present research is to study the effects of climate change on the variations in frequency and location of extreme weather events, analyzing atmospheric configurations that favor the occurrence of such events, with a special focus on Italy, due to their impact on the national electricity-energy system. Structures such as Rossby Wave Packets (RWPs) and atmospheric blocking events are recognized as precursors of extreme events (e.g., heat or cold waves, prolonged droughts, extreme precipitation events).

Rossby Wave Packets and atmospheric blocking are associated with deep depressions or intense persistent and stationary promontories. These phenomena have preferential climatological dispositions ( storm tracks for RWPs), whose modifications in amplitude, frequency and positioning can cause substantial changes to the local climate.

With reference to the state of the art, these atmospheric structures were characterized by applying consolidated methods shared in the literature to climatological reanalysis data (ERA5) and to the results of 10 numerical simulations of coupled atmosphere-ocean models of the latest generation (CMIP6).

First, the results obtained using ERA5 data were compared with those deduced through a multi-model mean (MMM) approach for the period 1986 – 2005. Then, once the performance of the MMM had been verified, the atmospheric configurations for future years were studied using the same methodology, developing short-term (2021 – 2040) and long-term (2081 – 2100) projections under the assumption of an extremely pessimistic business-as-usual socio-economic-emission scenario (SSP585), i.e., in the absence of policies aimed at reducing greenhouse gas emissions.

Although CMIP6 models generally underestimate the frequency of occurrence of RWPs and blocking events, the results obtained indicate, for the winter season, a long-term trend towards a higher frequency of intense RWPs over the European area and an increase in blocking events over Eastern Europe and nearby Asia, thus making extreme events such as floods or cold waves more likely in these areas and in the neighboring regions, including Italy. For other seasons in the Northern Hemisphere, a reduction in the frequency of RWPs is expected, while there are no clear signs regarding the frequency of atmospheric blocking events.