In Belgium, numerous cars have been washed away in storms.
In the city of Dinant, the vehicles carried away by the water blocked a level crossing, as the Belga news agency reported on Saturday evening, citing the railway company Infrabel.
The rail traffic had already stopped because of the flood in mid-July.
As the public broadcaster RTBF reported, the city of Namur in the province of the same name was also affected by floods.
The city is located around 100 kilometers west of Aachen.
Similar to Germany, there was a violent storm with fatalities in Belgium just over a week ago.
According to Friday figures, 36 people died and several people are still missing.
For North Rhine-Westphalia, the German Weather Service (DWD) does not expect a new storm disaster this weekend.
That said, meteorologist Jacqueline Kerrn on Saturday the German press agency in Düsseldorf.
This time, no prolonged heavy rain is to be expected across the board.
A first rain front with moderate precipitation had already reached southern parts of North Rhine-Westphalia by noon.
It also rained in the district of Euskirchen, in Bad Münstereifel and in Eftstadt-Blessem, which was particularly badly damaged by the storm of the century.
In individual areas that have already been damaged by floods, problems could arise from the evening onwards, when large amounts of rain flushed rubbish into the drains and thus blocked them.
There are still mountains of bulky waste on many streets.
In the early evening, the DWD issued an official level 2 warning of strong thunderstorms with gusts of wind around 70 kilometers per hour, heavy rain and hail.
According to the warning card, the Münsterland and northern parts of the Ruhr area were initially particularly affected.
The amount of precipitation was given as 20 to 30 liters per square meter within six hours.
For comparison: In the past week, extensive continuous rain with rain amounts of more than 150 liters per square meter caused the flood catastrophe in parts of North Rhine-Westphalia and Rhineland-Palatinate.