Intensiva regn i Malmö

Short-term intensive storms of duration up to an hour the years 1980–2007 from rain gauges in Malmö have
been analyzed to find intensities of long return periods. Non-dependent observations from different stations
have been combined into a series to which probability functions have been adjusted. The extreme events have
been investigated individually. The reliability of rain measurements is discussed. In order to investigate whether
rain intensities are different today compared to back in time, new and old rain data have been compared. Trends
over the last 20–25 years have been computed for two stations. It is found that 10–25 year long rain series from
single stations are too short to give good estimates of rains of long recurrence time, since a single event influ-
ences very much. However, there is a good fit to theoretical distributions if data from many stations are com-
bined; the number of station year increases. The largest observed rains in Malmö in the investigated period have
a return period of about 100 year. Rains of shorter return period than 10 year can be given as a simple relation
of duration and return period. Rain intensity curves 50 years old do not differ much from those derived from
new data. It is not possible to draw any conclusions about trends