Today, the newspapers’ fronts showed the destruction due to the torrential rain that yesterday was recorded in the state of North Rhine-Westfalia (NRW) and Rhineland-Palatinate (RP). Precipitation was so intense, that lead to major rivers overflow and local mass removal.
This situation generated the unfortunate dead of near 40 people, power outages, destruction of houses and disruptions in the trains/ highways transportation.
According to Dr. Bernhard Pospichal, meteorologist at the Institute of Geophysics and Meteorology at the University of Cologne. «The weather station Köln-Stammheim, for example, measured 154 mm in 24 hours. These are values that have never been measured in Cologne since 1945. The maximum daily precipitation quantity at Cologne station was 95 mm – once since 1945. This means that this time it was not only a little more, but really extremely much more» [read the complete interview here].
The picture show how much rain fell during this 24-hours period in Western Germany. Notice that the maximum rainfall reach 157 mm around 50 Km south of Cologne. Major differences are found between very close location. The airport of Bonh-Cologne reported 88 mm and a little more to the southeast, less of 30 mm were recorded.
The strong gradient between small areas indicate that the rainfall bands were almost stationary for several hours.
The area of major accumulation of rain seems to feet with a southwest-northeast band. In fact, synoptic analysis showed a low pressure system swirling in south Germany, maintaining a stable-permanent cyclonic circulation in the occlusion. In fact, the band of rainfall that affect NRW was an occluded front, almost semi-stationary trough 24-hours.
Water vapor from ERA5
José Vicencio [Meteorologist] 