Results highlight that the statistico-downscaling method is able to select LSCs leading to HPEs and to reproduce precipitating systems typical of Mediterranean events. This study also shows that it is possible to infer some conclusions about the evolution of the geographical location, occurrence and intensity of these intense events. The number of days with LSCs propitious to heavy precipitation significantly increases in the future climate. In particular, the simulated rainfall for the selected 21 cases shows an increase in the spatial variability of such events in the future climate associated with a slight increase of rainfall maxima.

We analysed the temporal evolution of heat wave frequency in the Paris region in a changing future climate (1960−1989, 2020−2049, 2070−2099). Firstly, a method for extracting heat waves from observed or simulated time series of daily minimum and maximum temperatures was proposed, based on heat-impact considerations. It was evaluated over the period 1951−2009 using observations from 2 meteorological stations of the Météo-France operational network. The past heat waves that have affected the Paris region were correctly identified in terms of both dates and durations. Eight heat waves were extracted from the data for this period of time (i.e. a mean frequency of about 1 in 7 yr). The method was then applied to a large sample of climate projections, including 1 regional climate model (RCM) following 3 emission scenarios (A2, A1B, B1) and 9 combinations of RCMs driven by different global circulation models following the A1B emission scenario only (from the European ENSEMBLES project). The historical runs generated 1 to 5 heat waves, depending on the model, with a median value of 3 events (i.e. a frequency of 1 in 10 yr). All models from the ENSEMBLES database simulated a systematic increase in the frequency of heat wave occurrences with time: 1 heat wave every 2 yr on average over 2020−2049, rising to at least 1, and up to 2, heat waves per year on average over 2070−2099. They also became much longer, with mean durations varying between 6 and 12 d over 2070−2099, and exceptional durations reaching 5 to 9 wk. A comparison of the heat waves simulated with the 3 different emission scenarios highlights the major impact of the scenario on the number of heat wave days (and the duration of heat waves) at the end of the 21st century. KEY WORDS: Heat waves · Regional climate models · Reference historical time series · Sources of uncertaintiesResale or republication not permitted without written consent of the publisher

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