A Historical European Windstorm Database from 1900 to 1940: The Windsurfer project Laura Zubiate (1) ([email protected]), Padraig Flattery (1), Len Shaffrey (2), Panos Athanasiadis (3), Ari Venalainen (4), George Emmanouil (5), Paula Camus (6), Oyvind Breivik (7) and Henk van den Brink (8) (1) Met Eireann, (2) University of Reading, (3) CMCC, (4) FMI, (5) NCRSD Demokritos, (6) IH Cantabria, (7) Met Norway, (8) KNMI INTRODUCTION THE STORMS . Storm 1: 13 - 14 In addition to loss of life, storms can cause significant damage Storm 2: 25 - 26 1902 – The Christmas Storm to infrastructure and industry Storm 3: 26 - 27 – The Yates & Ulysses Storm Storm 4: 2 - 3 February 1904 . The aim of this work is to collate all available information on Storm 5: 1 - 4 December 1909 – Triple Storm Storm 6: 16 - 17 February 1916 historical European windstorms including documentary Storm 7: 23 - 24 October 1921 - Ulvsund storm evidence, observations and reanalysis Storm 8: 28 February - 2 March 1923 Storm 9: 8 - 9 January 1924 – Tidal Wave . Assess early part of the 20th century (1900 – 1940) Storm 10: 7 - 8 October 1924 Storm 11: 21 - 23 December 1925 Storm 12: 28 January 1927 DATA Storm 13: 28 - 29 October 1927 – Lacken Disaster Storm 14: 6 - 7 January 1928 – Thames Flood REANALYSES Storm 15: 23 - 25 November 1928 Storm 16: 4 July 1929 Central Europe Storm Storm 17: 19 - 20 September 1930 Dataset Time span Temporal Spatial Resolution Authors Storm 18: 22 February 1935 Resolution Storm 19: 13 March 1937 Storm 20: 1 June 1938 ERA-20C 1900 - 2010 3 hourly ~ 125 km 91 levels ECMWF (Poli et al., 2016) Table 3. Complete list of storms described in the Historical Windstorm Database Figure 3. Various newspaper clippings providing accounts of storms between 1900 and 1940 20CR V2c 1851 - 2012 6 hourly 2 deg 28 levels NOAA (Compo et Figure 5. 20CR plot for al., 2011) 26/12/1902 at 0Z CERA-20C 1901 - 2010 3 hourly 125 km 91 levels ECMWF (Laloyaux et al., 2018) The first storm to hit Denmark in the 20th century is widely known as the ‘Christmas Storm’. A single Stone et al., 2019) C20C+ 1900-2017 monthly NA NA measurement from a balloon station from Hald in Midtjylland reported an hourly mean wind value of 35 Table 1. Reanalysis datasets that include the first half of the 20th century m/s (130 km/h), remarkably high for an inland station (DMI, 2018). The storm caused great damage to woodlands in Denmark, felling more trees than the Issues with reanalysis datasets previous large storm in 1894, 92% of the trees felled were pines. it is reported that damage was more severe. A comparison of ERA-20C and 20CR datasets highlights the key strengths of In addition to forestry damage, 300 roofs and 70 mills were destroyed in Denmark, and 15 people were killed ERA20C over 20CR in that it has a gap-free record for many climate variables, (Lamb & Frydendahl, 1991) uses a 4D assimilation scheme, and has a higher horizontal and vertical resolution. Drawbacks of ERA-20C are the possible introduction of spurious Figure 4. Pressure on the 26th December 1902 at factors due to a lack of data in the southern hemisphere in particular, and its 12h (Lamb and Frydendahl, 1991) weaknesses post-1979 where more comprehensive reanalysis products are available (Poli et al., 2017). https://climatedataguide.ucar.edu/climate-data/era- Figure 6. 20CR plot for 27/02/1903 at 6Z 20c-ecmwfs-atmospheric-reanalysis-20th-century-and-comparisons-noaas-20cr 26-27 February 1903 – The Yates & Ulysses Storm: Lamb & Frydendahl (1991, pp.152) report ‘great damage to buildings and trees’, with farmers’ hay ricks (stacks of hay) destroyed and cattle killed. 3000 trees were felled in Phoenix Park, Dublin (1000-3000 of which were elms according to different reports) and 4000 trees were felled on a Kilkenny estate. 2000 trees were uprooted at Birr, Co. Offaly (Met Éireann, 2019). Literature at the time referred to the storm, for instance the colophon (publisher blurb) at the end of ‘In the Seven Woods’ by W.B. Yates (Figure 26). This quote is then referred to in Ulysses by James Joyce when Buck Mulligan says: “Printed by the weird sisters in the year of the big Figure 7. Colophon for In the Seven Woods wind.” by WB Yates Figure 9. 20CR plot for 02/02/1909 at 12Z Figure 1. Air temperature anomalies from CRUTEM4, 20CRv2c and ERA-20C (from Poli et al., 01-04 December 1909 – Triple Storm: The series of storms caused many shipwrecks and significant loss of 2017) life (Lamb & Frydendahl, 1991). Roofs, chimneys and church steeples awere destroyed in many areas and trees awere uprooted. Rivers flooded and overflowed in OBSERVATIONS parts of northern France, along with train delays and a derailment in Vannes. Maritime navigation in French waters iwas severely disturbed, with several shipwrecks and at least a dozen drowned sailors (Meteo France, Dataset Time span Temporal Spatial Authors nd). Resolution Resolution Outside of France, the impacts in English waters were ISDB v4 1722 - 2015 Differs Point obs. Reanalysis.org (Cram et al., similar, where the material damage was enormous, and 2015) the sinking of two steamers caused the deaths of nearly MIDAS 1853 - 2019 Differs Point obs. UK Met Office (Met Office, 70 people. The German coast was severely affected and 2012) an estimated 50 people perished at sea (Meteo France, EMULATE collaboration, UK nd). EMULATE 1850 - 2003 Daily 5 deg Met Office (Ansell et al., 2006) Figure 8. Trajectory of depressions (Source: UK Met Office (Allan and http://tempetes.meteo.fr/spip.php?article151) HadSLP2 1850 - 2004 Monthly 5 deg Ansell, 2006) UK Met Office (Allan and HadSLP2r 1850 - present Monthly 5 deg Ansell, 2006) GHCNDaily 1861 - present Daily 5 deg NOAA (Menne et al., 2012) 4th July 1929 Central Europe Storm: Forestry damage is 2 deg since 1860, 1 NOAA (Freeman et al., 2017; ICOADS 1622 - present Monthly Smith et al., 2017) also well catalogued during this event as Hosek (1981) deg since 1960 reports 3,018,500 m3 of damaged timber, comprised of CRU MSLP 1873 - 2000 Monthly 5 lat. x 10 lon. 1,040,400 m3 in East Bohemia, followed by South Bohemia (886,100 m3) and South Moravia (444,900 (Harris et al., 2014) CRU TS v4.03 1901 - 2018 Monthly 0.5 deg m3). Damage was more serious in Bohemia than DP (abs) ~1830 - 2010 Monthly NA (Hanna et al., 2008) Moravia (Brazdil et al., 2004). Along with forestry, great damage was done to Table 2. Observational datasets that include the first half of the 20th century buildings, churches, industrial and other structures, fruit trees and gardens, railway transport, power cables and telephone lines, with at least 13 deaths in the Czech Lands and dozens of casualties (Brazdil et al., 2018).

Figure 11. Daily variations in air pressure, temperature, wind speed and wind Figure 10. 20CR plot for 04/07/1929 at 6Z direction at the Prague-Karlov station (a) 850 hPa-level wind (b), from Brazdil et al. (2018) CONCLUSIONS

 Images of 20CR v2c reanalysis data (Meteocentre, 2019) show the relative accuracy of the datasets in representing low pressure centres and storm characteristics, as most storms are clearly shown in the pressure graphs, indicating that the reanalysis datasets are useful in the assessment of historical storms

 This deliverable aimed to develop a historical European windstorm database, by collating all available information on surface windspeeds and creating an observational database of windstorms from 1900-1940

 The output of this is intended to feed in to other work packages on the WINDSURFER project, as well as data users, and the wider scientific community. These storms can be compared to future extreme winds from downscaled climate model runs (WP3), to assess potential trends in storminess or extremeness of storms in a warming world ACKNOWLEDGEMENT

th Figure 2. ISPD (top), USAF (bottom left) and TD_13 (bottom right) stations that contain data for the The WINDSURFER project started in September 15 2017 and will last for 36 months. It is part of ERA4CS, an ERA-NET period 1900-1940 initiated by JPI Climate and co-funded by the European Union. Grant no. 690462