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Spain is one of the leading tourist destinations worldwide, but also a climate change hot-spot. Weather conditions throughout the year have enabled the implementation of alternative outdoor leisure activities to beach-based tourism, helping to alleviate the strong seasonality. Climate is currently a positive resource but it could become a limiting factor for these activities in the future. Here, we assess the present and future conditions by adopting the second generation climate index for tourism (CIT) to quantify the climate potentials for cultural, golf, sailing, hiking, cycling and football activities. Present and future potentials are derived using observed and projected daily meteorological data from the ERA-5 reanalysis and the DMI-HIRHAM5 regional climate model (RCM) included in EURO-CORDEX project, respectively. A quantile–quantile adjustment is applied to the projected CIT data to correct biases at the local scale. Present climate potentials confirm the optimal conditions of the Spanish Mediterranean coast for practicing all the activities in spring and autumn, while in summer, ideal conditions only prevail for sailing. Projections show a general future increase of excellent climate potentials in winter and a general improvement of the weather assets in the northern half of the country during the shoulder seasons, except for cycling and football. [ABSTRACT FROM AUTHOR]

Medicanes, for Mediterranean hurricanes, are mesoscale cyclones with morphological and physical characteristics similar to tropical cyclones. Although less intense, smaller, and rarer than their Atlantic counterparts, medicanes are very hazardous events threatening islands and continental coasts within the Mediterranean Sea. The latest strong episode, Medicane Ianos (September 2020), resulted in severe damages in Greece and several casualties. This work investigates the oceanic response to these extreme events along the Mediterranean coasts under present‐day and future (late 21st century) climate conditions. To this end, a coupled hydrodynamic‐wave model is used to simulate both storm surges and wind‐waves generation and propagation in the Mediterranean Sea at high resolution (∼2 km) along the coastlines. A data set of thousands of medicanes synthetically generated from 20 global climate models and two atmospheric reanalyses is used to derive the atmospheric forcing fields. Regional coastal hazards assessment is performed for the present and future climates. For the first period, highest medicane‐induced waves are found in the central and the southwest part of the western Mediterranean, while greatest storm surges are found in the Adriatic Sea and regions characterized by wide and gently sloping continental shelves. Results obtained for future changes show amplitudes generally smaller than the associated uncertainty due to limited agreement among models (especially for coastal elevation). Though, model consensus is reached (60–75%) and relative intensity change is significant (10–20%) at some locations (e.g., 1 m increase of medicane‐induced significant wave height on average for south coasts of Sicilia). Plain Language Summary: Mediterranean hurricanes, medicanes, are tropical‐like cyclones generated in the Mediterranean basin that differ from their counterpart in the Atlantic in their smaller size and intensity. They rarely exceed 400 km of diameter and last generally 24–48 hr, unusually reaching intensities of category 1 hurricanes. A medicane is characterized by a warm core accompanied by thunderstorms, heavy rain, but also strong cyclonic winds (counter‐clockwise rotation) that are responsible for costly damages and often result in casualties. Furthermore, medicanes pose serious threats to coastal populations due to the storm surges, that is, the raising of the sea surface due to low atmospheric pressure, and to the combined effects of waves and winds along the coasts. This study investigates the coastal hazards induced by medicanes over the entire basin. To do so, we used a hydrodynamic and wave coupled model to simulate the generation and propagation of storm surges and wind‐waves over the Mediterranean Sea under the forcing of a set of thousands of synthetic medicanes that statistically describe the medicane climate for the present and future period (end of 21st century). Our results identify the most exposed coastal areas and quantify the current and projected return levels for waves and storm surges. Key Points: Mediterranean hurricanes (medicanes) generate largest wind‐waves (exceeding 10 m) in the central and the southwest part of the western basinWide and gently sloping continental shelves favor the generation of storm surges under medicane forcing with 100‐year return levels over 1 mProjected changes medicane‐induced coastal hazards are uncertain due to limited multimodel consensus, with some local exceptions [ABSTRACT FROM AUTHOR]

Most of the nature‐related economic costs and human losses in many regions of Europe are due to extreme weather events such as heat waves, cold spells, persistent droughts, heavy precipitation and intense cyclonic wind‐storms. Extreme precipitation events are projected by climatic models to become more intense over the continent while droughts might last longer by the end of the century. In dry regions as Southern Europe, soils are predicted to dry out as temperatures and evapotranspiration rise and rain‐bearing atmospheric circulations become less frequent. Prospects on the future of climate indices linked to extreme phenomena are herein derived by using observed and model projected daily meteorological data. Specifically, E‐OBS high resolution gridded datasets of observed precipitation and surface minimum and maximum temperatures have been used as the regional observed baseline. For projections, the same meteorological variables have been obtained from a set of regional climate models integrated in the European EURO‐CORDEX project, considering the RCP8.5 future emissions scenario. A quantile–quantile adjustment has been applied to the simulated regional scenarios to reduce biases in modelled extreme regimes. Results suggest that warm days will substantially increase across Europe, consistently with a decrease of cold nights. An increase in heat wave amplitude is expected across the continent, with South Eastern Europe and the Mediterranean as the most affected regions. In contrast, Northern Europe will undergo the largest decrease in cold spell magnitude. An overall rise in the frequency and volume of heavy precipitations is projected in all seasons, even if the number of dry days is also expected to increase, except in the Baltic countries. Regarding abnormally long dry periods (extreme droughts), we find that the occurrence of episodes would reduce over Europe as consequence of projected increases in length. [ABSTRACT FROM AUTHOR]

An extraordinary convective rainfall event, unforeseen by most numerical weather prediction models, generated a devastating flash flood (305 m 3 s -1) in the town of Sant Llorenç des Cardassar, Mallorca, on 9 October 2018. Four people died inside this village, while casualties were up to 13 over the entire affected area. This extreme event has been reconstructed by implementing an integrated flash flood modelling approach in the Ses Planes catchment up to Sant Llorenç (23.4 km 2), based on three components: (i) generation of radar-derived precipitation estimates, (ii) modelling of accurate discharge hydrographs yielded by the catchment (using FEST and KLEM models), and (iii) hydraulic simulation of the event and mapping of affected areas (using HEC-RAS). Radar-derived rainfall estimates show very high agreement with rain gauge data (R2=0.98). Modelled flooding extent is in close agreement with the observed extension by the Copernicus Emergency Management Service, based on Sentinel-1 imagery, and both far exceed the extension for a 500-year return period flood. Hydraulic simulation revealed that water reached a depth of 3 m at some points, and modelled water depths highly correlate (R2=0.91) with in situ after-event measurements. The 9 October flash flood eroded and transported woody and abundant sediment debris, changing channel geomorphology. Water velocity greatly increased at bridge locations crossing the river channel, especially at those closer to the Sant Llorenç town centre. This study highlights how the very low predictability of this type of extreme convective rainfall events and the very short hydrological response times typical of small Mediterranean catchments continue to challenge the implementation of early warning systems, which effectively reduce people's exposure to flash flood risk in the region. [ABSTRACT FROM AUTHOR]

During the hydrological year 2015-2016 (September to August) a severe drought affected the Balearic Islands, with substantial consequences (alleviated partially by desalination plants) on water availability for consumption from reservoirs and aquifers and also on the vegetation cover. In particular, a plague of Xylella fastidiosa reached an alarming level for almond and olive trees. The expansion of this infestation could be attributed to, or at least favored by, the extreme drought. In this paper we analyze this anomalous episode in terms of the corresponding water balance in comparison with the balance obtained from long-term climatological data. It is shown that the drought was the result of a lack of winter precipitation, the lowest in 43 years, which led to a shortage of water storage in the soil. In several meteorological stations analyzed, evaporation was greater than precipitation during all the months of the year. In terms of attribution, it is found that during the 2015-2016 winter the atmospheric circulation over the North Atlantic was largely westerly and intense, with high values of the NAO index that were reflected in high pressures over the Iberian Peninsula and the western Mediterranean. [ABSTRACT FROM AUTHOR]

Flash floods are common in small Mediterranean watersheds and the alerts provided by real-time monitoring systems provide too short anticipation times to warn the population. In this context, there is a strong need to develop flood forecasting systems in particular for developing countries such as Morocco where floods have severe socio-economic impacts. In this study, the AROME (Application of Research to Operations at Mesoscale), ALADIN (Aire Limited Dynamic Adaptation International Development) and WRF (Weather Research and Forecasting) meteorological models are evaluated to forecast flood events in the Rheraya and Ourika basin located in the High-Atlas Mountains of Morocco. The model evaluation is performed by comparing for a set of flood events the observed and simulated probabilities of exceedances for different precipitation thresholds. In addition, two different flood forecasting approaches are compared: the first one relies on the coupling of meteorological forecasts with a hydrological model and the second one is a based on a linear relationship between event rainfall, antecedent soil moisture and runoff. Three different soil moisture products (in-situ measurements, European Space Agency's Climate Change Initiative ESA-CCI remote sensing data and ERA5 reanalysis) are compared to estimate the initial soil moisture conditions before flood events for both methods. Results showed that the WRF and AROME models better simulate precipitation amounts compared to ALADIN, indicating the added value of convection-permitting models. The regression-based flood forecasting method outperforms the hydrological model-based approach, and the maximum discharge is better reproduced when using the WRF forecasts in combination with ERA5. These results provide insights to implement robust flood forecasting approaches in the context of data scarcity that could be valuable for developing countries such as Morocco and other North African countries. [ABSTRACT FROM AUTHOR]

The Mediterranean region is a unique area characterized by a large spectrum of atmospheric phenomena, some of which have a high impact on many aspects of human activities, safety and wellbeing. The area is long considered as a hot spot of such atmospheric phenomena deserving multidisciplinary scientific attention. The scientific research that has been carried out on these high impact atmospheric processes that occur in the Mediterranean area is indeed widespread and the available international literature is very extensive. The paper touches initially the temperature and precipitation regimes, followed by a discussion of floods and droughts. The exciting cyclogenetic patterns of explosive cyclones and medicanes are presented in separate sections. The lightning activity and the presence of dust and other pollutants are also presented herein. The atmospheric chemistry of the region which is increasingly becoming of utmost importance for the area under study is distinctly discussed. Attempts to modify the weather (the precipitation, in particular) are outlined too. The effects of climatic change on various atmospheric processes are considered throughout this paper, in addition to a dedicated section on temperature and precipitation. [ABSTRACT FROM AUTHOR]