Extreme Rain Events in Mid-Latitudes

Extreme precipitation (rain) and subsequent flooding is a major environmental hazard. Methods have been developed, mainly on a statistical basis, to estimate maximum probable or even maximum possible precipitation. Higher resolution weather forecast models, with complex representation of the physical processes involved, can be used for calculation of maximum precipitation. This requires input data with known probabilities, but also allows for estimation of the sensitivities of relevant parameters. Orographic (mountain) structures are a major influence in the formation of very high precipitation. The model applied here is used to study the sensitivity of orographic influence. The long-term climatic development of heavy precipitation and floods in Europe during recent centuries will be used to illustrate these numerical studies.