The severe thunderstorm of 4 October 2007 in Mallorca: an observational study

During the afternoon of 4 October 2007, a thunderstorm swept across the Island of Mallorca from southwest to northeast. Strong straight-line winds (up to 30 m/s) and heavy rain (rates up to 100 mm/h) were registered accompanying the storm. Tornadoes with an estimated intensity of F2–F3 developed nearby the city of Palma, severely affecting industrial installations. One person was killed by the impact of heavy debris while more than 10 million € in damages were attributed to the event in the industrial area only. The observed evolution of temperature, humidity, wind and pressure, as well as the sequence of radar images, reveal that a squall line was initially organized over the sea and then moved north-eastwards at an estimated speed of around 80 km/h. This paper presents an analysis of the event from an observational point of view. The aim of the study is to contribute to the characterization of these rare events in the Western Mediterranean by analyzing the observational information available for this particular extreme event. The diagnosis is aimed at helping forecasters to identify this kind of organized deep convective events and being able to issue timely warnings. The synoptic scenario shows warm and moist advection at low levels over Balearics and an upper-level trough over mainland Spain. This situation is known to be prone to deep convection in Mediterranean Spain in autumn. Radiosonde ascents from Murcia and Palma show convective instability at mid levels that can conduce to develop convection if appropriate ascents occur. A plausible lifting mechanism to trigger convection is attributed to large amplitude gravity waves, registered as short-period pressure oscillations by surface barographs

A deep cyclone of African origin over the Western Mediterranean: diagnosis and numerical simulation

International audienceFrom 19 to 22 December 1979, a deep cyclone evolved over the Western Mediterranean. Gusty winds of more than 30 m/s, as well as a strong pressure decrease to about 990 hPa were recorded in Palma de Mallorca (Balearic Islands, Spain). ECMWF analyses are used for a diagnosis and numerical study of the case. Sensitivity experiments using the HIRLAM model are performed to assess the role of the surface sensible heat flux, latent heat release and orography on the genesis and evolution of the cyclone. At synoptic scale, the situation is governed by the instability of an upper-level short wave. The cyclone developed within a notable baroclinic environment, which resulted from a cold advection from the northwest towards North Africa. The baroclinicity at first stages of the cyclogenesis is quantified by means of the Eady model. At latter stages, the evolution of the potential vorticity structures at high levels reveals a wide tropopause fold over the cyclone, as well as the presence of a strong anomaly associated with the low-level system. Sensitivity experiments reveal a notable cyclogenetic role of the latent heat release throughout the atmosphere in the deepening of the low, whereas no significant effect of the surface sensible heat flux is obtained for the simulation interval. On the other hand, an unusual cyclolytic role can be attributed to the northern ranges of the Mediterranean basin. Effectively, the low enlargement and deepening is constrained by a "wall effect", which is a consequence of the interaction of the cyclonic flow and those northern mountainous systems

Towards a climatology of sensitivities of Mediterranean high impact weather ? first approach

International audienceDuring recent years, great interest has grown within the operational weather community on the adaptable component of observational networks. Decisions regarding where to deploy new observations of special value under threatening weather, or regarding permanent changes in observational strategies need support from sensitivity studies that determine areas where the addition of observations would optimally improve the skill of numerical predictions. Within the context of the MEDEX project (http://medex.inm.uib.es), the sensitivities of a collection of severe weather episodes in the Mediterranean have been computed using the MM5 Adjoint Modeling system. Various approaches are explored trying to summarize the results for the diversity of cases that produce high impact weather (HIW; mainly heavy rain and strong winds) in the Mediterranean region. A first attempt uses an objective classification of the trajectories of the most intense cyclone types from the ERA-40 reanalyses. Sensitivities are then computed for each group of frequent trajectories, providing a prototype sensitivity field for each of the most frequent intense cyclones in the Mediterranean. However, a large portion of HIW episodes in the Mediterranean are not linked to significantly intense cyclones within the climatology. Consequently, a subjective classification of HIW events is also performed and the sensitivity fields for an example case is shown to complete the study. Although the sensitive areas for Mediterranean HIW are not particularly confined, it is remarkable how poorly sampled areas by the regular observing networks such as North Africa and the eastern North-Atlantic are highlighted in the results

Numerical study of the October 2000 torrential precipitation event over eastern Spain: analysis of the synoptic-scale stationarity

International audienceA torrential precipitation event affected eastern Spain during 21 to 24 October 2000. Total accumulated rainfall higher than 500 mm was registered at some locations, with values up to 300 mm in a 24-h period. The synoptic-scale charts for these days show the presence of a cold cutoff low aloft, south of the Iberian Peninsula, as a part of an W-blocking structure over Europe. At low levels, persistent easterly winds, established between a dominant anticyclone over eastern Europe and a cyclone over Morocco, are found over the western Mediterranean throughout the entire period. Satellite images show the advance and breaking away of a trough, with an associated cold front, over the Iberian Peninsula, which resulted in the cutoff low formation. Later, scattered convective cells are detected along the eastern Spanish coast during more than 3 days. Numerical simulations reveal that the convective environment was developed by the low-level advection of warm and moist air from central Mediterranean, being charged of moisture by evaporation from the sea. Sensitivity runs confirm that the synoptic-scale persistent low-level easterly flow, and specifically, the presence of a low level jet, was crucial for the subsynoptic processes leading to the long lasting torrential rainfall over the exposed terrains of eastern Spain. The stagnancy of the low-level flow is attributed to the quasi-stationary characteristics of the upper level cutoff low located south of the Iberian Peninsula. Experiments with modified upper-level potential vorticity distributions reveal that slight deviations from the observed configuration result in enhanced mobility of the low-level flow pattern, and thereby a reduction of the precipitation persistence. This suggests the major importance of a correct representation in the model initial conditions of the intensity and location of the upper level features, in order to obtain valuable numerical forecasts of these heavy rainfall events

Predictability of prototype flash flood events in the Western Mediterranean under uncertainties of the precursor upper-level disturbance

International audienceThe HYDROPTIMET case studies 9-10/06/2000 Catalogne, 8-9/09/2002 Cévennes and 24-26/11/2002 Piémont encompass prototype flash-flood situations in the western Mediterranean, attending to the relevant synoptic and mesoscale signatures identified on the meteorological charts. A prominent mid-tropospheric trough or cut-off low can be identified in all events prior and during the period of heavy rains, which clearly served as the precursor agent for the onset of the flash-flood conditions and the cyclogenesis at low levels. Being aware of the uncertainty in the representation of the upper-level disturbance and the necessity to cope with it within the operational context when attempting to issue short to mid-range numerical weather predictions of these high impact weather events, a systematic exploration of the predictability of the three selected case studies, subject to uncertainties in the representation of the upper-level precursor disturbance, is carried out in this paper by means of numerical simulations

Predictability of prototype flash flood events in the Western Mediterranean under uncertainties of the precursor upper-level disturbance: the HYDROPTIMET case studies

International audienceThe HYDROPTIMET case studies (9?10 June 2000 Catalogne, 8?9 September 2002 Cévennes and 24?26 November 2002 Piémont) appear to encompass a sort of prototype flash-flood situations in the western Mediterranean attending to the relevant synoptic and mesoscale signatures identified on the meteorological charts. In Catalogne, the convective event was driven by a low-pressure system of relatively small dimensions developed over the mediterranean coast of Spain that moved into southern France. For Cévennes, the main circulation pattern was a synoptic-scale Atlantic low which induced a persistent southerly low-level jet (LLJ) over the western Mediterranean, strengthened by the Alps along its western flank, which guaranteed continuous moisture supply towards southern France where the long-lived, quasistationary convective system developed. The long Piémont episode, very representative of the most severe alpine flash flood events, shares some similarities with the Cévennes situation during its first stage in that it was controlled by a southerly moist LLJ associated with a large-scale disturbance located to the west. However, these circulation features were transient aspects and during the second half of the episode the situation was dominated by a cyclogenesis process over the Mediterranean which gave place to a mesoscale-size depression at surface that acted to force new heavy rain over the slopes of the Alps and maritime areas. That is, the Piémont episode can be catalogued as of mixed type with regard to the responsible surface disturbance, evolving from a large-scale pattern with remote action (like Cévennes) to a mesoscale pattern with local action (like Catalogne). A prominent mid-tropospheric trough or cut-off low can be identified in all events prior and during the period of heavy rain, which clearly served as the precursor agent for the onset of the flash-flood conditions and the cyclogenesis at low-levels. Being aware of the uncertainty in the representation of the upper-level disturbance and the necessity to cope with it within the operational context when attempting to issue short to mid-range numerical weather predictions of these high impact weather events, a systematic exploration of the predictability of the three selected case studies subject to uncertainties in the representation of the upper-level precursor disturbance is carried out in this paper. The study is based on an ensemble of mesoscale numerical simulations of each event with the MM5 non-hydrostatic model after perturbing in a systematic way the upper-level disturbance, in the sense of displacing slightly this disturbance upstream/downstream along the zonal direction and intensifying/weakening its amplitude. These perturbations are guided by a previous application of the MM5-adjoint model, which consistently shows high sensitivities of the dynamical control of the heavy rain to the flow configuration about the upper-level disturbance on the day before, thus confirming the precursor characteristics of this agent. The perturbations are introduced to the initial conditions by applying a potential vorticity (PV) inversion procedure to the positive PV anomaly associated with the upper-level disturbance, and then using the inverted fields (wind, temperature and geopotential) to modify under a physically consistent balance the model initial fields. The results generally show that the events dominated by mesoscale low-level disturbances (Catalogne and last stage of the Piémont episode) are very sensitive to the initial uncertainties, such that the heavy rain location and magnitude are in some of the experiments strongly changed in response to the "forecast errors" of the cyclone trajectory, intensity, shape and translational speed. In contrast, the other situations (Cévennes and initial stage of the Piémont episode), dominated by a larger scale system wich basically acts to guarantee the establishment and persistence of the southerly LLJ towards the southern France-north Italy orography, exhibit much higher predictability. That is, the slight modifications in the LLJ direction and intensity encompassed by the ensemble of perturbed forecasts are less critical with respect to the heavy precipitation potential and affected area

Gender differences in mental health during the economic crisis

Background: Economic crises have a negative effect on mental health. Little evidence has been published on the impact of economic downturns on male and female. The aim of the study was to analyze gender differences in specific mental disorders in primary care during the current economic recession in Spain. Method: A total of 7, 914 patients in 2006 and 5, 876 patients in 2010 were recruited to collect sociodemographic data and the Primary Care Evaluation of Mental Disorders. Results: Between 2006 and 2010 the prevalence of Major Depressive Disorder increased 155.7% in men and 104.9% in women; Generalized Anxiety Disorder increased 98.3% in men and 71.3% in women; and Multisomatoform Disorder increased 100.05% in men and 37% in women. The effect of the Employment confounder was significant across all comparisons: Major Depressive Disorder Generalized Odds Ratio=2.557 for Men (p<.001), 2.046 for Women (p=.002); Generalized Anxiety Disorder Generalized Odds Ratio= 2.153 (p<.001) for Men, 1.546 for Women (p<.001); and for Non-specific Multisomatoform Disorder Generalized Odds Ratio=1.680 for Men (p<.001) and 1.301 for women (p=.014). Conclusion: Overall prevalence of mental disorders increased significantly between 2006 and 2010, especially in males, who are more sensitive to the effect of the current economic recession than women. Antecedentes: el impacto de las crisis económicas sobre la salud mental está bien documentado, pero hay poca evidencia sobre el efecto diferencial que pueda tener entre hombres y mujeres. El objetivo fue analizar las diferencias de género en la prevalencia de trastornos mentales en atención primaria durante la recesión económica en España. Método: 7.914 pacientes en 2006-2007 y 5.876 en 2010-2011 fueron encuestados para recoger datos sociodemográficos y completar la entrevista Primary Care Evaluation of Mental Disorders. Resultados: entre 2006 y 2010 la prevalencia del Trastorno Depresivo Mayor incrementó 155, 7% en hombres y un 104, 9% en mujeres; el Trastorno de Ansiedad Generalizada aumentó 98, 3% en hombres y 71, 3% en mujeres; el Trastorno Multisomatomorfo incrementó 100, 05% en hombres y 37% en mujeres. El desempleo fue significativo en todos los análisis: Trastorno Depresivo Odds Ratio Generalizados= 2.557 en hombres (p<.001), 2.046 en mujeres (p= .002); Trastorno de Ansiedad Generalizada Odds Ratio Generalizados= 2.153 (p<.001) en hombres, 1.546 en mujeres (p<.001); Trastorno Multisomatoformo indiferenciado Odds Ratio Generalizados= 1.680 en hombres (p<.001) y 1.301 en mujeres (p= .014). Conclusiones: la prevalencia de los trastornos mentales se incrementó entre 2006 y 2010 en ambos sexos, pero especialmente en hombres, quienes son más sensibles a los efectos de la crisis económica

A new approach to sensitivity climatologies: the DTS-MEDEX-2009 campaign

Adaptive observation is an approach to improving the quality of numerical weather forecasts through the optimization of observing networks. It is sometimes referred to as Data Targeting (DT). This approach has been applied to high impact weather during specific field campaigns in the past decade. Adaptive observations may involve various types of observations, including either specific research observing platforms or routine observing platforms employed in an adaptive way. The North-Atlantic TReC 2003 and the EURORISK-PREVIEW 2008 exercises focused on the North-Atlantic and Western Europe areas using mainly routine observing systems. These campaigns also included Mediterranean cases. &lt;br&gt;&lt;br&gt; The most recent campaign, DTS-MEDEX-2009, is the first campaign in which the DT method has been used to address exclusively Mediterranean high impact weather events. In this campaign, which is an important stage in the MEDEX development, only operational radiosonde stations and commercial aircraft data (AMDAR) have provided additional observations. Although specific diagnostic studies are needed to assess the impact of the extra-observations on forecast skill and demonstrate the effectiveness of DTS-MEDEX-2009, some preliminary findings can be deduced from a survey of this targeting exercise. &lt;br&gt;&lt;br&gt; After a description of the data targeting system and some illustrations of particular cases, this paper attempts some comparisons of additional observation needs (through effectively deployed radio-soundings) with sensitivity climatologies in the Mediterranean. The first step towards a sensitivity climatology for Mediterranean cases of high impact weather is indirectly given by the frequency of extra-soundings launched from the network of radiosonde stations involved in the DTS-MEDEX-2009 campaign