Proposal of three thermodynamic variables to discriminate between storms associated with hail and storms with intense rainfall in Catalonia

DOI: 10.3369/tethys.2013.10.03

Tethys no. 10 pp.: 25 - 34


Between late spring and early fall, the development of storms is common in Catalonia. Despite the fact that they usually produce heavy showers of short duration, they can also involve severe weather with ice pellets or hail. While the latter usually affect inland regions, and there are numerous publications on these cases; the analysis of events affecting the coast and causing damage to public and private properties is not so well developed. The aim of this study is to provide additional thermodynamic indicators that help differentiate storms with hail from storms without hail, considering cases that have affected various regions of Catalonia, mainly coastal areas. The aim is to give more information to improve prognosis and the ability to detail information in these situations. The procedure developed involved the study of several episodes of heavy rainfall and hail that hit Catalonia during the 2003-2009 period, mainly in the province of Girona, and validated the proposal during the campaign of late summer and fall of 2009, as well as 2012. For each case, several variables related to temperature, humidity and wind were analyzed at different levels of the atmosphere, while the information provided by the radio sounding in Barcelona was also taken into account. From this study, it can be concluded that the temperature difference between 500 hPa and 850 hPa, the humidity in the lower layers of the atmosphere and the LI index are good indicators for the detection of storms with associated hail.


  • - Aran, M., Sairouni, A., Bech, J., Toda, J., Rigo, T., Cunillera, J., and Moré, J., 2007: Pilot project for intensive surveillance of hail events in Terres de Ponent (Lleida), Atmos Res, 83, 315–335, doi: 10.1016/j.atmosres.2005.09.013.
  • - Aran, M., Peña, J. C., and Torà, M., 2011: Atmospheric circulation patterns associated with hail events in Lleida (Catalonia), Atmos Res, 100, 428–438, doi: 10.1016/j.atmosres.2010.10.029.
  • - Atencia, A., Mediero, L., Llasat, M. C., and Garrote, L., 2011: Effect of radar rainfall time resolution on the predictive capability of a distributed hydrologic model, Hydrol Earth Syst Sci, 15, 3809–3827, doi: 10.5194/hess-15-3809-2011.
  • - Barnolas, M. and Llasat, M. C., 2007: A flood geodatabase and its climatological applications: the case of Catalonia for the last century, Nat Hazards Earth Syst Sci, 7, 271–281, doi: 10.5194/nhess-7-271-2007.
  • - Barrera, A., Altava-Ortiz, V., Llasat, M. C., and Barnolas, M., 2007: Heavy rain prediction using deterministic and probabilistic models. The flash flood cases of 11-13th October 2005 in Catalonia (NE of Spain), Advances in Geosciences, 12, 121–126, doi: 10.5194/adgeo-12-121-2007.
  • - Bernal, M., 2008: Aplicación de un SIG al análisis espacial de las tormentas de granizo en el NE de la Península Ibérica, Universitat de Barcelona, Barcelona, treball del Màster Oficial en Meteorologia.
  • - Boshoms, M., 2008: Tempestes de calamarsa a Catalunya. Cap a la creació duna base de dades depisodis de calamarsa. Anàlisi temporal per al període (1996-2006), Universitat de Barcelona, Barcelona, treball del Màster Oficial en Meteorologia.
  • - Brooks, H. E. and Craven, J. P., 2002: A database of proximity soundings for significant severe thunderstorms, 1957-1993, American Meteorological Society, Preprints, 21st Conference on Severe Local Storms, San Antonio, TX, 639-642.
  • - Ceperuelo, M., Llasat, M. C., López, L., García, E., and Sánchez, J. L., 2006: Study of 11 September 2004 hailstorm event using radar identification of 2D systems and 3D cells, Advances in Geosciences, 1, 215–222, doi: 10.5194/adgeo-7-215-2006.
  • - Ceperuelo, M., Rigo, T., Llasat, M. C., and Sánchez, J. L., 2009: Improving hail identification in the Ebro valley region using radar observations: probability equations and warning thresholds, Atmos Res, 93, 474–482, doi: 10.1016/j.atmosres.2008.09.039.
  • - Dessens, J., Berthet, C., and Sánchez, J. L., 2007: A point hailfall classification based on hailpad measurements: The ANELFA scale, Atmos Res, 83, 132–139, doi: 10.1016/j.atmosres.2006.02.029.
  • - Farnell, C., Aran, M., Andrés, A., Busto, M., Pineda, N., and Torà, M., 2009: Study of the September 17th 2007 severe hailstorm in Pla d’Urgell. Part I: fieldwork and analysis of the hailpads, Tethys, 6, 69–81, doi: 10.3369/tethys.2009.6.05.
  • - Galway, J. G., 1956: The lifted index as a predictor of latent instability, Bull Amer Meteorol Soc, 37, 528–529.
  • - Gibergans-Bàguena, J. and Llasat, M. C., 2007: Improvement of the analog forecasting method by using local thermodynamic data. Application to autumn precipitation in Catalonia, Atmos Res, 86, 173–193, doi: 10.1016/j.atmosres.2007.04.002.
  • - Kain, J. S. and Fritsch, J. M., 1993: Convective parameterization for mesoscale models: The Kain-Fritsch scheme, in: The representation of cumulus convection in numerical models, Emanuel, K. A. and Raymond, D. J., Meteorological Monograph of the American Meteororological Society, 46, 165-170.
  • - Kunz, M., 2007: The skill of convective parameters and indices to predict isolated and severe thunderstorms, Nat Hazards Earth Syst Sci, 7, 327–342, doi: 10.5194/nhess-7-327-2007.
  • - Llasat, M. C. and Corominas, J., 2010: Riscos associats al clima. Segon informe sobre el canvi climàtic a Catalunya, J.E. Llebot (coord.), Institut d’Estudis Catalans i Generalitat de Catalunya, Departament de la Vicepresidència, Consell Assessor per al Desenvolupament Sostenible de Catalunya, pp. 243-307, ISBN (IEC): 978-84-9965-027-2, ISBN (Gencat): 978-84-393-8615-5, Dip`osit Legal: B. 44160-2010, 2010.
  • - Llasat, M. C., Llasat-Botija, M., and López, L., 2009: A press database on natural risks and its application in the study of floods in northeastern Spain, Nat Hazards Earth Syst Sci, 9, 2049–2061, doi: 10.5194/nhess-9-2049-2009.
  • - López, L., 2003: Convección atmosférica severa: pronóstico e identificación de tormentas de granizo, Universidad de León, tesis doctoral, 207 pp.
  • - Martín, F., Elizaga, F., Carretero, O., and San Ambrosio, I., 2007: Diagnóstico y predicción de la convección profunda, STAP Nota técnica Núm. 35.
  • - McGingley, J., 1986: Nowcasting Mesoscale Phenoma, ed. P.S. Ray, American Meteorological Society, Boston, Massachussets, 657-688.
  • - Merino, A., 2009: Caracterización termodinámica de la atmósfera en situaciones de granizo en el valle medio del Ebro y comparación con otras regiones de formación de tormentas, Universitat de Barcelona, Barcelona, treball del Master Oficial en Meteorologia.
  • - Miller, R. C., Bidner, A., and Maddox, R. A., 1972: Notes on analysis and severe storm forecasting procedures of the air force global weather control, AFGWC Tech. Rep 200, Air Weather Service, US Air Force, 102 pp.
  • - Mitzeva, R., Dimitrova, T., and Savtchenco, A., 2007: Enviromental conditions responsible for the type of precpitation in summer convective over Bulgaria, Faculty of Physics, University of Sofia and Agency Hail Suppression, Sofia, Bulgaria.
  • - Pineda, N., Aran, M., Andres, A., Busto, M., Farnell, C., and Torà, M., 2009: Study of the September 17th 2007 severe hailstorm in Pla d’Urgell. Part II: meteorological analysis, Tethys, 6, 83–103, doi: 10.3369/tethys.2009.6.06.
  • - Rigo, T., 2004: Estudio de sistemas convectivos mesoescalares en la zona mediterránea occidental mediante el uso de radar meteorológico, tesis doctoral, 215 pp.
  • - Rigo, T. and Llasat, M. C., 2007: Analysis of mesoscale convective systems in Catalonia using radar for the period 1996-2000, Atmos Res, 83, 458–472, doi: 10.1016/j.atmosres.2005.10.016.
  • - San Ambrosio, I., 2001: Primera valoración de algoritmos para la estimación de la probabilidad de ocurrencia de granizo, V Simposio Nacional de Predicción. Memorial “Alfonso Ascaso”, Madrid 20-23 Noviembre 2001, 6 pp.
  • - Sánchez, J. L., Fernández, M. V., Fernández, J. T., Tudurí, E., and Ramis, C., 2003: Analysis of mesoscale convective systems with hail precipitation, Atmos Res, 67-68, 573–588, doi: 10.1016/S0169-8095(03)00074-7.
  • - Weisman, M. L. and Klemp, J. B., 1986: Characteristics of Isolated Convective Storms. Mesoscale Meteorology and Forecasting, Ed. P.S. Ray, American Meteorological Society, Boston, Massachussets, 331-358.
  • - Witt, A., Eilts, M. D., Stumpf, G. J., Johnson, J. T., Mitchell, E. D., and Thomas, K. W., 1998: An enhanced hail detection algorithm for the WSR-88D, Weather Forecast, 13, 286–303, doi: 10.1175/1520-0434(1998)013<0286:AEHDAF>2.0.CO;2.

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 Unported License

Indexed in Scopus, Thomson-Reuters Emerging Sources Citation Index (ESCI), Scientific Commons, Latindex, Google Scholar, DOAJ, ICYT (CSIC)

Partially funded through grants CGL2007-29820-E/CLI, CGL2008-02804-E/, CGL2009-07417-E and CGL2011-14046-E of the Spanish Ministry of Science and Innovation