At the time of Wegener, European scientists and meteorologists were leading the research on tornadoes. This situation changed after 1950, driven by the tornado forecast advances of Miller and Fawbush and the United States surpassed Europe as a result. In this presentation, we present the context of Wegener's research on tornadoes by summarizing the contribution to tornado research by European scientists since Classical Antiquity (e.g., Aristotle; Lamy 1689; Boscovich 1749; Peltier 1840) and by summarizing the main theories on tornado formation (i.e., volcanic theory, downburst theory, electrical theory, waves theory, thermodynamic theory, mechanical theory).
Based on Wegener’s correspondence with Wladimir Köppen (1846–1940) during 1915–1916, we are able to piece together for the first time the origin and the main sources for Wind- und Wasserhosen in Europa. Finally, the main results from Wegener (1917) are analyzed in the context of the international research on tornadoes and waterspouts at the beginning of the 20th Century.