For its time, the most comprehensive survey of tornado events in
Germany, Austria, and Switzerland appeared in Alfred Wegener's book
Wind-und Wasserhosen in Europa (Wegener 1917). The earliest
event cited in that compilation for the area was in 1586. Wegener's
monograph counted 119 events in the region.
Subsequent to World War I there have been numerous outstanding
tornadic occurrences and several compilations of tbe activity. This
paper brings together an up-to-date listing of tornadoes in the area,
accompanied by an analysis of the significant characteristics
of the climatology. Similar analyses for other European
countries (TORRO, Dessens and Snow 1989) revealed the need to obtain
such a data record for the above-mentioned three countries as
well.
Stimulated both by studies of tornado research in Germany during
the twentieth century (Peterson 1992) and Doppler radar analyses of a
tornadic small supercell storm in 1995 (Hannesen et al. 1998), an
effort was made to bring the existing scattered data records on
tornadic storms in the three countries together. The final goal of
this effort is to gain insight in the spatial and temporal
distribution of the storms and to provide a better understanding of
the interaction of severe local storms and topography. This may then
be used to explain the existence of tornado alleys.
This study has bed several results. Tornadoes do occur several
times a year in Germany, Switzerland,and Austria, much more
frequently than generally believed by the public in these countries.
Strong or violent tornadoes are quite rare, but nevertheless present a
great threat due to the high population density in Central Europe. A
dominant influence of topography on spatial distribution of tornadic
storms becomes apparent and may be used for improved forecasts of
severe thunderstorms in the near future.
References:
Dessens, J., and J. T. Snow, 1989: Tornadoes in France. Wea.
Forecasting, 4, 110-132.
Hannesen, R., N. Dotzek, H. Gysi, and K. D. Beheng, 1998: Case study
of a tornado in the Upper Rhine Valley. Meteorol. Z., N.
F. 7, in press.
Peterson, R. B., 1992: Johannes Letzmann: a pioneer in the studies of
tornadoes. Wea. Forecasting, 7, 166-184.
TORRO: Tornado and Storm Research Organization;
http://www.torro.org.uk/
Wegener, A., 1917: Wind-und Wasserhosen in Europa .
Vieweg, Braunschweig, 301 pp.
NO. 877 D05