Tornadoes on the territory of the Czech Republic : From early medieval chronicles to the “ internet society ”

This paper addresses the historical documentation of tornadoes and the awareness of tornadic events in the area of the present Czech Republic throughout the last nine centuries. The oldest records of tornado occurrence in the region can be found in chronicles from the first half of the 12 century – the two most interesting of these are presented here in original Latin texts. Several other cases of possible tornadoes and waterspouts can be found in chronicles from the 12 and 13 centuries. However, from the descriptions of the events it is not always clear if the phenomenon was a tornado, waterspout, dust swirl, or if it was of a non-tornadic nature. From the 14 to 19 centuries the tornado records are rather scarce for the region. However, this is likely to have a non-meteorological explanation. Gregor Mendel’s (1871) essay "Die Windhose vom 13. October 1870" can be considered as a distinctive "breakpoint" in the documentation history of tornadoes in the territory of the present Czech Republic, followed later by the work of Wahlburg (1911) and Wegener (1917). During the “socialist” period the term ”tornado” was rarely used and they were poorly understood, producing a view that "tornadoes do not occur in Central Europe". The situation began to change with the works of Munzar (1993) and Šálek (1994), and new records showed that about one tornado per year occurred between 1994 and 1999. Finally, between 2000 and 2002, the number of documented tornadoes in the Czech Republic was between 5 and 8 cases per year. This increase is a result of several important factors which are discussed in detail in the last section of this paper. This paper is a compilation of authors’ presentations at the Toulouse “Eurotornado 2000” and Praha “ECSS 2002” conferences, which are combined to summarise the complex tornado history and present stage of tornado documentation and research in the area of the Czech Republic.