Forecasts for the weekend: “Normal thunderstorms” – dangerous in flood areas

At the weekend there is another threat of thunderstorms in the flood areas in North Rhine-Westphalia and Rhineland-Palatinate. Because many dams are destroyed and the soil there is soaked, even comparatively small amounts of rain could be dangerous.

The people in the regions affected by the flood disaster are threatened with heavy rain again this weekend. In North Rhine-Westphalia there should be heavy rain showers and thunderstorms again. As the German Weather Service (DWD) announced, there is a risk of storms due to heavy rain on Saturday afternoons and evenings.

It is still unclear where exactly the storms could occur. “A precise localization of the focal points will – if at all – only be possible at very short notice,” said the DWD.

Rain up to 40 liters per square meter

Also in Rhineland-Palatinate and Saarland, meteorologists are expecting heavy showers and thunderstorms again this weekend. According to the forecast of the DWD, heavy heavy rain with rain amounts of up to 40 liters per square meter must be expected on Saturday.

According to the forecast, there can be the first, local heavy rainfalls in the southwest of Rhineland-Palatinate and Saarland with a rainfall of up to 15 liters per square meter by Saturday morning. In Bavaria, too, severe storms could lead to heavy rainfall again – and thus raise the levels of the rivers again.

No more dikes, no more retention basins

Also the ARD weather expert Tim Frühling reckons with amounts of rain between 20 and 40 liters per square meter. These are actually normal amounts of rain in a summer thunderstorm, according to spring tagesschau24. The problem is if the thunderstorm hits the hard-hit floodplains, then it hits a landscape in which the safety systems have been destroyed. There are no more dykes, no more dams and also no rain retention basins.

In this area such thunderstorms would not have been a problem two weeks ago, said Frühling. But in this case it is possible that the water masses will be washed back into the towns, into the valleys and into the houses.

Local storms that move on

For Saturday, spring expects areas in the Allgäu, Baden-Württemberg, Hesse, Rhineland-Palatinate and North Rhine-Westphalia to be affected. Which places will be spared and which will be hit cannot yet be foreseen. But it will be local storms that move on. They would not last as long and as widespread as a week ago.

Soil saturation is the big problem

But that doesn’t mean the problem is over, says Frühling. Because the floors are a big problem. In the direction of the Eifel and Rhineland, the soils are already 80 percent to 90 percent saturated, and they can no longer absorb much. Larger amounts of rain would then immediately be transferred to the rivers and streams.

The situation is also problematic in the south and east. In the direction of the Erzgebirge and the edge of the Alps, there would still be 100 percent soil saturation. These soils could no longer absorb anything, said Frühling. That is the area that is at risk on Sunday and Monday. The storms continued eastwards, there was a risk that everything that came from the sky would end up in the streams and rivers.

Better preparation from everyone

Wolfram Geier from the Federal Office for Civil Protection and Disaster Assistance demanded that everyone should better prepare for floods together – including the authorities. The citizens would have to deal with it, but the economy and infrastructure operators would also have the task of dealing with the extreme weather conditions and developing protection concepts.

No experience with heavy rain events

The civil protection is well prepared for normal flood situations, explained Geier tagesschau24. Normal floods would have a long lead time, so preparations were underway. But no experience has yet been gained with heavy rain events like last week. These are new dimensions that cannot yet be optimally prepared. Especially on the Ahr, there were extensive, extensive and extremely long precipitation phases with enormous amounts. This has never been seen before, says Geier.

Don’t save your belongings – save yourself

The expert recommends that people need to be informed and sensitized more quickly. The people would then have to obey the orders of the authorities immediately. But you also have to protect yourself adequately. The right measures would have to be taken: So don’t save the car, don’t get your belongings out of the basement. The advice is that one should rescue oneself to higher areas as soon as possible.

Stronger cooperation and renaturation

In view of the dangers and threats to which we are exposed, we need much stronger cooperation. According to Geier, you need daily cooperation between the federal, state, local and emergency organizations in order to be able to give the crisis teams and political decision-makers the right recommendations.

In addition to the creation of rain retention basins, the renaturation of streams and rivers must progress. Renaturation means that the flow speed of streams is reduced.

And, according to Geier, you have to carry out heavy rain risk mapping. It must be recorded where the threats from heavy rain could arise. If necessary, commercial and residential areas also have to be relocated.