Precipitation

Elbe_without and Elbe_with.jpgThese two satellite images of the region between Torgau and Wittenberg (Eastern Germany) give an idea of the extent of the Elbe flood in August 2002. Elbe_without.jpg was taken on 14 August, whereas Elbe_with.jpg shows the situation on 20 August 2004.

The pictures taken from the helicopter show the aftermath of the flood. For example the image of Dresden presents the flooding of the Zwinger in the foreground.

Images taken by Meteosat: The satellite movie consisting of Meteosat images shows the development of clouds between 6 and the 16 August 2002 as an example for a weather situation which is called Five-B by meteorologists. Hereby a cyclone passes the Golf of Genoa in northern direction. Usually low pressure systems travel from the Atlantic Ocean to the west. But here the cyclone "Ilse" was drawn southward by the anticyclone over the Azores at the same time its regular passage was blocked by a cold front in the North.

Therefore it moved to the South passing Spain to the Golf of Genoa. If it moves further towards northern directions, it can initiate intense rainfalls in Austria and the regions situated in the North-East of it. Most commonly these V-B weather situations occur in spring and autumn. If this happens in summer, the ocean is warm and more water evaporates from it. The warm air absorbs more water vapour and is capable to carry it. This results in warm and very humid air masses which can cause flooding - as it happened at the Oder in the summer of 1997. In 2002 the whole effect was even stronger, since not only one cyclone occurred, but several ones in series as clearly shown in the movie. When the precipitations of the first cyclone saturated the ground, it cannot absorb the water of the second one anymore and the rivers have to carry the whole charge. In 1988 and 1995 Rhine floods happened in spring and winter, but they derived from different weather situations.

Elbe_without and Elbe_with.jpg: The images were taken from the Journal Der Spiegel, Article "Building up the East: The Billion Flood", Edition 35/02

Dresden1+2.jpg: Source in the WWW

Meteosat film sequence: PDUS data of EUMETSAT