Weather

Weather warnings: know more Precisely where it crashes

The German weather service has introduced a new, more precise prediction System. Severe weather warnings will not be sent immediately for the country as a whole but also for individual cities and municipalities.

At the end of June, a Thunderstorm over a fixed terrain. The Festival could be cancelled in a timely manner.

“The rooster crows on the dung, the weather, or it remains as it is.” This verballhornte German farmer, as a rule, points in a humorous way on a Problem that meteorologists traditionally have: In the case of any weather forecast, it is not, or only partially true there are almost always areas for this prediction.

This is especially critical for severe weather warnings, such as black ice, heavy rain with risk of Flooding, hurricane, heavy snowfall or thunderstorms. Because then citizens, fire brigade and civil protection need to react – risk areas, such as forests avoid areas susceptible to Flooding to evacuate, or just to better stay at home.

If the announced storm, it remains only a stronger Wind

The severe weather does not occur, but then even, it can be quite embarrassing as of this year, during the rose Monday parade in Düsseldorf. The was
because of an announced storm has been cancelled. Afterwards, the Düsseldorfer not arguing about whether it was an Overreaction. It was the day a little windier than usual, but no longer a really dangerous storm.

Germany is positioned in terms of severe weather warnings, and have been for some time very well. The German weather service (DWD) has been able to get a warning system, with the Concerned severe weather warnings for certain parts of the country via Email, as a SMS to mobile phone or via a Smartphone App. In comparison to most other European countries, the warning net was already very detailed and designed.

The district of Main-Kinzig huge. So far, all the municipalities have been warned – even if the storm was local.

Warnings only in the you really need

But it’s even better. Therefore, the DWD has refined his System now. In the future, warnings may not be in favour of all the counties, but for individual municipalities. In Germany there are about 400 districts, but 10,000 municipalities. Thus, the System is about 25 times more precise.

“It has been shown that there is a warning on the Basis of counties often too coarse,” says DWD meteorologist Hans-Joachim Koppert “There are counties, since almost 70 kilometres between the Eastern and Western edge. When we warn of a Storm in a district that is created at the East end, sees a citizen on the Western end maybe just a blue sky.”

So the weather warning in the future: Only where the Thunderstorm with heavy rain occurs, there is a warning.

The previous System was tailored to the organization of civil protection. And is organized at the County level. But this is not understood by many citizens, says Koppert: “The thinking then: What is this?”

Another example Is about a warning of heavy squalls for areas high up in the mountains, it is pointless to warn a huge district, the largest surface area of which is deeper located. Then, it is sufficient to warn only the one place that is really on a high level.

Not all of the computers, let

The early detection of thunderstorms remains for Hans-Joachim Koppert is the biggest challenge

The calculation of the weather models to pick. They process a huge amount of measurement data from all over the world. But then the hand follows: “We put the people to a place where he generates a real added value and a significant improvement in this prediction system can achieve,” says Koppert. The key to a precise storm warning meteorologist with his understanding of the weather situation.

And not every prediction is equally simple. “If we have a rain location or a winter storm low with high wind speeds, we can warn days in advance, because this Situation is relatively predictable,” says the meteorologist. But with summer thunderstorms. “The atmosphere is not know yet, where you can be in two or three hours of a Thunderstorm. As chaotic events in the exercise are really. We can say that a Thunderstorm just before, if it is at the least see approach.”

The three-dimensional views of the atmosphere

But Koppert is confident that it will be also for such difficult to predict in the future solutions. Already now it is possible, with a dense network of low-impact-a nearly three-dimensional picture of the atmosphere radars to generate, to detect the density of rain, snow or misty precipitation at different heights.

In the future, data from existing GPS ground stations, this image could accumulate. You could provide information on the three-dimensional distribution of humidity in the atmosphere. This is possible because the radio path between the ground is influenced station and the satellite due to the humidity.

To the extent that it is not yet, but the regional more accurate severe weather warnings are now each on the DWD website. A new severe weather Warning App, then from the beginning of August ready.