In my previous post I have shown the spatial distribution of tornadoes in Europe based on tornado reports between 20042013. I have chosen this interval because this is the interval during which the European Severe Weather Database has been actively collecting tornadoes and waterspouts reports in Europe (the operational phase of  ESWD started in 2006). The efforts of the ESWD were not concentrated only on the recent events, but also on collecting historical tornado and waterspout reports. To show the history of tornado observations in Europe, I have animated the spatial distribution of tornadoes and waterspouts in five year intervals between 18002013 using data from ESWD.

The spatial distribution of tornadoes and waterspouts in Europe in five years intervals between 18002013 based on data from the European Severe Weather Database. The new tornado and waterspout reports are represented in orange and the previous reports in blue.

The animation starts from zero in 1800. However, this does not signify that tornadoes were not reported before the XIX century, but only that between 18001804 we do not have any records of tornadoes or waterspouts in Europe. In fact,  tornadoes have been reported in Europe since the beginning of the XI century. The earliest tornado reported in Europe occurred at Rosdalla (near Kolbeggan) in Ireland on 30 April 1054.  A systematic documentation of tornadoes and waterspouts began in the XIX century. Before the XIX century there are only three notable contributions to the study of European tornadoes. The first is a study by the French theologian François Lamy in which "physical conjectures" on the formation of tornadoes (in particular on the formation of a tornado that occurred near Reims, France on 10 August 1680) are presented. The second is a "physical-mathematical dialogue" by the Italian astronomer Geminiano Montanari describing a tornado that occurred on 29 July 1686 over Mantova, Padova and Verona (northern Italy). The third is a study by Roger Joseph Boscovich of a tornado that occurred in Rome (Italy) on the night between 11 and 12 June 1749.  

If we return now to the animation and we focus only on the reports before the 1930, we observe that the majority of these reports came from France and Germany. This is not surprising if we take into account the research on tornadoes in this two countries. 

In France, Jean Charles Athanase Peltier published in 1840 a study entitle Météorologie: Observations et recherches expérimenta les sur les causes qui concourent à la formation des trombes" (Meteorology: Observations and experimental research on the causes that contribute to the formation of tornadoes ).  Peltier, who began his career as watchmaker and watch dealer, later become interested in experimental physics (electrodynamics in particular, see Peltier effect), atmospheric electricity and meteorology. In his book, Peltier does not only critically discuss the major theories from the XIX century on the formation of tornadoes, but also does an excellent job of collecting and analysing tornado reports from Europe. Thus, his study contains what is probably the first tornado climatology for Europe.

Alfred Lothar Wegener, a German meteorologist and polar researcher, mainly remembered today for advancing the theory of continental drift, continued Peltier's work of collecting tornado and waterspout reports in Europe.  While recuperating in a military hospital in Berlin from an injury he suffered as a German soldier during World War I, Wegener developed his comprehensive study of tornadoes and waterspouts in Europe. Published in 1917, Wind- und Wasserhosen in Europa (Tornadoes and waterspouts in Europe) is a classic of tornado research literature. Based on tornado and waterspout reports between 1456 and 1916 (258 reports), Wegener estimated that at least 100 tornadoes and waterspouts are observed each year in Europe. In my previous post I have estimated, using tornado reports from ESWD, that in average 233 tornadoes were reported each year (between 20042013) in Europe. In a recent study, Groenemeijer and Kühne estimated using data from ESWD, that on average approximately  480 tornadoes and waterspouts are reported across Europe each year (between 20062013).

If we return again to the animation and focus this time on the reports after 1930, we observe that most of these reports still came from Western Europe and that there is a lack of tornado reports over Eastern Europe. This lack of tornado reports is associated with non-meteorological factors. For example, in some socialist countries from Eastern Europe (e.g., Romania) the word tornado was forbidden in the official meteorological reports and in the mass media. After 1990, there is an increase in the number of reports over entire Europe, due to increased data collections efforts and increased public awareness.  

In my next posts, I will discuss in more details the early contributions to tornado research in Europe. If you are aware of any historical efforts on collecting and analysing tornado reports in your country I will be interested to here from you. 


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AuthorBogdan Antonescu
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We know that approximately 1000 tornadoes are observed each year in the United States, but how many tornadoes are observed each year in Europe?  As part of my current research project (funded by AXA Research Fund) and trying to provide an answer to this question in order to assess the threat of severe convective storms (those producing tornadoes, large hail, severe wind gusts and lightning) over Europe. 

Tornado databases are maintained by few European countries and thus is difficult to evaluate the number of tornadoes that occur each year in Europe. Recently, a new pan-European tornado database has become available that will allow a step-change in our ability to observe and understand tornadoes in Europe. Thus, in my research I am using tornado data from the European Severe Weather Database (ESWD), a unique database of severe-weather maintained by European Severe Storm Laboratory (ESSL). The ESWD is a joint effort between National Meteorological and Hydrological Services and voluntary observers. Also, the public can contribute with observations (submitting a severe weather report to ESWD is very easy and it takes around 5 min. and you can make a contribution to science).

Based on the data from ESWD, 2338 tornadoes were reported between 1 January 2004 and 31 December 2013 in Europe (EU countries and Norway, Belarus, Ukraine, Moldova, Serbia, Bosnia and Herzegovina, Cyprus and Turkey). Thus, approximately 233 tornadoes are observed each year in Europe

Next, we can ask what is the spatial distribution of tornadoes in Europe? To answer this question, I have plotted the annual average number of tornado per square kilometre at NUTS 3 level for EU countries and at the national level for non-EU countries (Fig. 1).  Thus, most of the tornadoes are reported over Northern and Central Europe.

Figure 1. The annual average number of tornadoes per square kilometres (shaded according to the scale) at NUTS 3 level for EU countries and at the national level for non-EU countries. (click on the image to explore the details) 

Figure 1. The annual average number of tornadoes per square kilometres (shaded according to the scale) at NUTS 3 level for EU countries and at the national level for non-EU countries. (click on the image to explore the details) 

The spatial distribution of tornadoes in Fig. 1 depends not only on the meteorological factors associated with the tornado occurrence (e.g., Markowski and Richardson 2014)  but also on non-meteorological factors like the population density. Figure 2 shows the average population density between 2004 and 2013 for Europe based on the data from EUROSTAT.

Figure 2. The average population density (inhabitants per square kilometre, shaded according to the scale) between 2004 and 2013 based on the data from EUROSTAT. (click on the image to explore the details)

Figure 2. The average population density (inhabitants per square kilometre, shaded according to the scale) between 2004 and 2013 based on the data from EUROSTAT. (click on the image to explore the details)

The high population density over Northern and Central Europe, Italy or United Kingdom may result in more tornadoes begin reported since more people are living in those areas. Thus, there is a population influence on tornado reports in Europe. In my next post I will discuss this influence and how to account for the population bias.

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AuthorBogdan Antonescu
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