A regional simulation of the severe precipitation episode which gave rise to the floods in the eastern part of Central Europe during July 1997 was performed using the meso-&bgr;-scale weather prediction model DM of Deutscher Wetterdienst. It is shown that the model reproduces the mesoscale precipitation distribution reasonably well as verified against available rain gauge observations. It is therefore used to investigate the transport routes of the bulk of moisture which led to the wide spread heavy precipitation. Inspection of the atmospheric water budget highlights the importance of the cyclonic advection of moist mediterranean air for the formation of strong precipitation in Central Europe. Autochthonous influences are comparably small. ¿ 1999 American Geophysical Union