An updated estimate of tornado occurrence in Europe

Results from a survey on average tornadic activity in Europe conducted among the participants of the European Conference on Severe Storms (ECSS) 2002 are presented. Compared to Alfred Wegener's estimate of "at least 100 tornadoes per year in Europe" the present survey shows a total of 329 +/- 12 tornadoes over land and water per year based on observations, and more than twice as many cases (697 +/- 36) for an estimate of the expected true climatological number, accounting for present underreporting in many European countries. Traditionally, European tornado numbers include waterspouts. For comparison to the current number of 1170 observed tornadoes over land per year in the USA, the European numbers are 169 +/- 9 per year based on observations, and 304 +/- 25 based on estimates. As European severe weather research is rapidly developing, one can expect less underreporting in the future, leading to an augmented database for upcoming surveys like the present one. (C) 2003 Elsevier B.V. All rights reserved.