NHESS Natural Hazards and Earth System Sciences NHESS Nat. Hazards Earth Syst. Sci. 1684-9981 Copernicus Publications Göttingen, Germany 10.5194/nhess-14-2487-2014 The XWS open access catalogue of extreme European windstorms from 1979 to 2012 Roberts J. F. 1 Champion A. J. https://orcid.org/0000-0001-7451-3552 2 Dawkins L. C. 3 Hodges K. I. 4 Shaffrey L. C. https://orcid.org/0000-0003-2696-752X 5 Stephenson D. B. 3 Stringer M. A. 2 Thornton H. E. 1 Youngman B. D. 3 Met Office Hadley Centre, Exeter, UK Department of Meteorology, University of Reading, Reading, UK College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK National Centre for Earth Observation, University of Reading, Reading, UK National Centre for Atmospheric Science, University of Reading, Reading, UK 22 09 2014 14 9 2487 2501 Copyright: © 2014 J. F. Roberts et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://nhess.copernicus.org/articles/14/2487/2014/nhess-14-2487-2014.html The full text article is available as a PDF file from https://nhess.copernicus.org/articles/14/2487/2014/nhess-14-2487-2014.pdf

The XWS (eXtreme WindStorms) catalogue consists of storm tracks and model-generated maximum 3 s wind-gust footprints for 50 of the most extreme winter windstorms to hit Europe in the period 1979–2012. The catalogue is intended to be a valuable resource for both academia and industries such as (re)insurance, for example allowing users to characterise extreme European storms, and validate climate and catastrophe models. Several storm severity indices were investigated to find which could best represent a list of known high-loss (severe) storms. The best-performing index was <i>S</i><sub>ft</sub>, which is a combination of storm area calculated from the storm footprint and maximum 925 hPa wind speed from the storm track. All the listed severe storms are included in the catalogue, and the remaining ones were selected using <i>S</i><sub>ft</sub>. A comparison of the model footprint to station observations revealed that storms were generally well represented, although for some storms the highest gusts were underestimated. Possible reasons for this underestimation include the model failing to simulate strong enough pressure gradients and not representing convective gusts. <br><br> A new recalibration method was developed to estimate the true distribution of gusts at each grid point and correct for this underestimation. The recalibration model allows for storm-to-storm variation which is essential given that different storms have different degrees of model bias. The catalogue is available at <a href=" http://www.europeanwindstorms.org" target ="_blank"> http://www.europeanwindstorms.org </a> .

 References Beljaars, A. C. M.: The Influence of Sampling and Filtering on Measured Wind Gusts, J. Atmos. Ocean. Technol., 4, 613–626, 1987. Berrisford, P., Dee, D., Poli, P., Brugge, R., Fielding, K., Fuentes, M., Kållberg, P., Kobayashi, S., Uppala, S., and Simmons, A.: ERA report series: The ERA-Interim archive, version 2.0, Tech. rep., ECMWF, 2011. Bessemoulin, P.: Les têmpetes en France, Annales des Mines, 9–14, 2002 (in French). Born, K., Ludwig, P., and Pinto, J. G.: Wind gust estimation for Mid-European winter storms: towards a probabilistic view, Tellus A, 64, 17471, <a href="http://dx.doi.org/10.3402/tellusa.v64i0.17471">https://doi.org/10.3402/tellusa.v64i0.17471</a>, 2012. Brasseur, O.: Development and application of a physical approach to estimating wind gusts, Mon. Weather Rev., 129, 5–25, 2001. Browning, K. A.: The sting at the end of the tail: Damaging winds associated with extratropical cyclones, Quart. J. Roy. Meteorol. Soc., 130, 375–399, 2004. Cavicchia, L., von Storch, H., and Gualdi, S.: A long-term climatology of medicanes, Clim. Dynam., 43, 1183–1195, <a href="http://dx.doi.org/10.1007/s00382-013-1893-7">https://doi.org/10.1007/s00382-013-1893-7</a>, 2013. Compo, G. P., Whitaker, J. S., Sardeshmukh, P. D., Matsui1, N., Allan, R. J., Yin, X., Gleason, B. E., Vose, R. S., Rutledge, G., Bessemoulin, P., Brönnimann, S., Brunet, M., Crouthamel, R. I., Grant, A. N., Groisman, P. Y., Jones, P. D., Kruk, M. C., Kruger, A. C., Marshall, G. J., Maugeri, M., Mok, H. Y., Nordli, O., Ross, T. F., Trigo, R. M., Wang, X. L., Woodruff, S. D., and Worley, S. J.: The Twentieth Century Reanalysis Project, Quart. J. Roy. Meteorol. Soc., 137, 1–28, 2011. Davies, T., Cullen, M. J. P., Malcolm, A. J., Mawson, M. H., Staniforth, A., White, A. A., and Wood, N.: A new dynamical core for the Met Office's global and regional modelling of the atmosphere, Q. J. Roy. Meteorol. Soc., 131, 1759–1782, 2005. Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S. B., Hersbach, H., Hólm, E. V., Isaksen, L., Kållberg, P., Köhler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M., Morcrette, J. J., Park, B. K., Peubey, C., de Rosnay, P., Tavolato, C., Thépaut, J. N., and Vitart, F.: The ERA Interim reanalysis: configuration and performance of the data assimilation system, Q. J. Roy. Meteorol. Soc., 137, 553–597, 2011. Della-Marta, P. M., Mathis, H., Frei, C., Liniger, M. A., Kleinn, J., and Appenzeller, C.: The return period of wind storms over Europe, Int. J. Climatol., 29, 437–459, 2009. Donat, M. G., Leckebusch, G. C., Wild, S., and Ulbrich, U.: Benefits and limitations of regional multi-model ensembles for storm loss estimations, Clim. Res., 44, 211–225, 2010. ECMWF: IFS documentation – Cy31r1 operational implementation, Tech. rep., ECMWF, available at: <a href="http://www.ecmwf.int/research/ifsdocs/CY31r1">http://www.ecmwf.int/research/ifsdocs/CY31r1</a>, last access: December 2013, 2006. Fink, A. H., Brücher, T., Ermert, V., Krüger, A., and Pinto, J. G.: The European storm Kyrill in January 2007: synoptic evolution, meteorological impacts and some considerations with respect to climate change, Nat. Hazards Earth Syst. Sci., 9, 405–423, <a href="http://dx.doi.org/10.5194/nhess-9-405-2009">https://doi.org/10.5194/nhess-9-405-2009</a>, 2009. Haylock, M. R.: European extra-tropical storm damage risk from a multi-model ensemble of dynamically-downscaled global climate models, Nat. Hazards Earth Syst. Sci., 11, 2847–2857, <a href="http://dx.doi.org/10.5194/nhess-11-2847-2011">https://doi.org/10.5194/nhess-11-2847-2011</a>, 2011. Hodges, K. I.: Feature Tracking on the Unit Sphere, Mon. Weather Rev., 123, 3458–3465, 1995. Hodges, K. I.: Adaptive Constraints for Feature Tracking, Mon. Weather Rev., 127, 1362–1373, 1999. Hodges, K. I., Lee, R. W., and Bengtsson, L.: A Comparison of Extratropical Cyclones in Recent Reanalyses ERA Interim, NASA MERRA, NCEP CFSR, and JRA-25, J. Climate, 24, 4888–4906, 2011. Hoskins, B. J. and Hodges, K. I.: New Perspectives on the Northern Hemisphere Winter Storm Tracks, J. Atmos. Sci., 59, 1041–1061, 2002. Howard, T. and Clark, P.: Correction and downscaling of NWP wind speed forecasts, Met. Apps., 14, 105–116, 2007. Klawa, M. and Ulbrich, U.: A model for the estimation of storm losses and the identification of severe winter storms in Germany, Nat. Hazards Earth Syst. Sci., 3, 725–732, <a href="http://dx.doi.org/10.5194/nhess-3-725-2003">https://doi.org/10.5194/nhess-3-725-2003</a>, 2003. Lamb, H. H.: Historic Storms of the North Sea, British Isles and Northwest Europe, Cambridge University Press, 1991. Landsea, C. W., Anderson, C., Charles, N., Clark, G., and Dunion, J.: The Atlantic Hurricane Database Reanalysis Project: Documentation for 1851–1910 Alterations and Additions to the HURDAT Database, in: Hurricanes and typhoons: Past, present and future, edited by: Murnane, R. J. and Liu, K.-B., Columbia University Press, 2004. Leckebusch, G., Renggli, D., and Ulbrich, U.: Development and application of an objective storm severity measure for the Northeast Atlantic region, Meteor. Z., 17, 575–587, 2008. Levinson, D. H., Diamond, H. J., Knapp, K. R., Kruk, M. C., and Gibney, E. J.: Toward a Homogenous Global Tropical Cyclone Best-Track Dataset, B. Am. Meteorol. Soc., 91, 377–380, 2010. Lock, A. and Edwards, J.: Unified Model documentation paper 24: The paratetrization of boundary layer processes, Tech. rep., Met Office, 2013. Mailier, P. J., Stephenson, D. B., Ferro, C. A. T., and Hodges, K. I.: Serial Clustering of Extratropical Cyclones, Mon. Weather Rev., 134, 2224–2240, 2006. Manganello, J., Hodges, K. I., Kinter-III, J. L., Cash, B. A., Marx, L., Jung, T., Achuthavarier, D., Adams, J. M., Altshuler, E. L., Huang, B., Jin, E. K., Stan, C., Towers, P., and Wedi, N.: Tropical Cyclone Climatology in a 10-km Global Atmospheric GCM: Toward Weather-Resolving Climate Modeling, J. Climate, 25, 3867–3893, 2012. Panofsky, H. A., Tennekes, H., Lenschow, D. H., and Wyngaard, J. C.: The characteristics of turbulent velocity components in the surface layer under convective conditions, Bound.-Lay. Meteorol., 11, 355–361, 1977. Pinheiro, J. and Bates, D.: Mixed-Effects Models in S and S-PLUS, Springer, 2000. Sheridan, P.: Review of techniques and research for gust forecasting and parameterisation: Forecasting Research Technical Report 570, Tech. rep., Met Office, 2011. Sigma: No 1/2004: Many fatalities, comparatively moderate insured losses, Tech. rep., Swiss Reinsurance Copmany, 2004. Sigma: No 2/2006: Natural catastrophes and man-made disasters in 2005, Tech. rep., Swiss Reinsurance Copmany, 2006. Sigma: No 2/2007: Natural catastrophes and man-made disasters in 2006: Low insured losses, Tech. rep., Swiss Reinsurance Copmany, 2007. Sigma: No 2/2009: Natural catastrophes and man-made disasters in 2008: North America and Asia suffer heavy losses, Tech. rep., Swiss Reinsurance Copmany, 2009. Sigma: No 1/2011: Natural catastrophes and man-made disasters in 2010: A year of devastating and costly events, Tech. rep., Swiss Reinsurance Copmany, 2011. Sigma: No 2/2012: Natural catastrophes and man-made disasters in 2011: Historic losses surface from record earthquakes and floods, Tech. rep., Swiss Reinsurance Copmany, 2012. Sigma: No 2/2013: Natural catastrophes and man-made disasters in 2012: A year of extreme weather events in the US, Tech. rep., Swiss Reinsurance Copmany, 2013. Stephenson, D. B.: Chapter 1: Definition, diagnosis, and origin of extreme weather and climate events, in: Climate extremes and society, edited by: Murnane, R. and Diaz, D., Cambridge University Press, 2008. Strachan, J., Vidale, P.-L., Hodges, K., Roberts, M., and Demory, M.-E.: Investigating Global Tropical Cyclone Activity with a Hierarchy of AGCMs: The Role of Model Resolution, J. Climate, 26, 133–152, 2013. Ventrice, M. J., Thorncroft, C. D., and Janiga, M. A.: Atlantic Tropical Cyclogenesis: A Three-Way Interaction between an African Easterly Wave, Diurnally Varying Convection, and a Convectively Coupled Atmospheric Kelvin Wave, Mon. Weather Rev., 140, 1108–1124, 2012.