Ein Wasserfall im Himmel: Gewitter im Mai und Fallstreifen

Mai ist oft die Zeit kurzlebiger Gewitter und kühlerer Regentage in Mitteleuropa. Seit einigen Jahren jedoch treten auch vermehrt Extremwettersituationen mit Sturzfluten und sogar Tornados auf. 2018 war besonders ungewöhnlich, da es bereits im April neue Temperaturrekorde gegeben hat. Es war in vielen Regionen zu trocken und ist es immer noch. Eine großes Problem ist der Umstand, dass langanhaltender Regen immer mehr fehlt. Dieser Landregen gerade im Mai ist normalerweise typisch für unser Wetter. Auch wenn er für Touristen wenig erfreulich ist, so ist er doch für die Natur und die Landwirtschaft lebenswichtig. Das hat sich geändert. Wie es die Klimaforscher vorhergesagt haben, kommt es stattdessen wenn zu Schauern und Gewittern mit kurzzeitigen Sturzfluten.

Ich erinnere mich noch, dass der Mai kein sonderlich warmer Monat war, als ich noch jünger war. In manchen Jahren lag sogar in den Alpen noch viel Schnee. In der Mitte des Monats war es oft kalt. Doch dieses Jahr war der ganze Mai eher wie Mittsommer statt wie ein Frühlingsmonat.

In Süddeutschland endete die trockene Periode im Mai, als vermehrt Schauer und Gewitter auftraten.

Das erste Gewitter in meiner Umgebung, dem Ammersee in Oberbayern entwickelte sich am 12. Mai.

Dieses Gewitter war sehr beeindruckend, denn die tiefstehende Sonne beleuchtete die Wolken und den Regen von unten.  Der Mai ist genau für solche Aufnahmen von Gewittern, da das Licht günstiger als im Hochsommer ist. Ebenso ist die Luft oft klarer als im Juli. Zudem ist das durch die Lichtbedingungen eine gute Zeit, Niederschlagsstreifen unter den Schauerwolken zu fotografieren.  Diese Fallstreifen lassen manchmal sehr interessante Muster entstehen.

An den folgenden Tagen kam es zu weiteren Gewittern. Die Wetterdienste hatten eine harte Zeit im Mai. Einige Male wurde warmes, stabiles Wetter vorher gesagt. Doch immer wieder kam es anders. An Pfingsten, dem 20. und 21. Mai,  sollte es warm und trocken werden, aber es folgten weitere Schauer und Gewitter. Insbesondere der 20. Mai sollte eigentlich warm und trocken sein. Stattdessen war es ein dunkler Tag, wo es durch einen heftigen Gewittersturm sogar zu einer Sturzflut in einem kleinen Ort zwischen Murnau und Garmisch-Partenkirchen kam. Bereits am 18. Mai musste ein Open-Air Event in Fürstenfeldbruck in der Nähe von München wegen eines Unwetter abgesagt werden.

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Hier sieht man nun, was am 20. Mai, einem Sonntag, geschah: Am Nachmittag war der Himmel voller dunkler Wolken und es regnete.  Im Bild sieht man den Hohen Peissenberg im Hintergrund, an dem Nebelfetzen hochzogen. Im Süden war ein Gewitter zu sehen, das zu der besagten Überflutung führte. Erst am Abend beruhigte sich das Wetter.

Der 21. Mai begann mit Nebel. Eine tief hängende Schicht hing zwischen den Bergen und dem davor liegenden Land. Durch die starke Sonne lichtete sich der Nebel rasch und der Himmel wurde klar:
Die Luft war immer noch feucht und die Sonne heiß – perfekte Bedingungen für die Entwicklung weiterer Gewitter. Am Nachmittag bewegte sich eine starke Gewitterzelle Richtung Ammersee. Dieses Gewitter erwies sich wegen der Fallstreifen und einem Regenbogen als sehr interessantes Motiv.

Es fiel auf, dass dieses Jahr die Gewitter oft in ungewöhnliche Richtungen zogen. Manchmal kamen sie aus Südosten und bewegten sich nach Südwesten oder sie zogen von Norden nach Süden. Meistens ziehen die Wettersysteme in Europa eigentlich von West nach Ost. Eine ungewöhnliche Konstellation von Drucksystemen war die Grund für diese Entwicklungen und auch für die lange Trockenheit. Zu diesem Zeitpunkt ahnte allerdings noch niemand, welche Dimensionen diese Anomalie 2018 annehmen würde.

Das Gewitter am 21. Mai kam für einige Zeit näher, stoppte dann aber scheinbar. Ein Grund dafür ist, dass der See das lokale Wetter beeinflusst.

In so einem Fall ist es immer gut, schon im Voraus ein paar gute Aussichtspunkte zu kennen. Das machte es leichter, die Wetterentwicklungen zu verfolgen.

Eine höhere Position in der Landschaft war besonders hilfreich, den Regenbogen zu entdecken, der sich während des Gewitters entwickelte.

Anfangs war dieser Regenbogen kaum zu sehen, wurde dann aber stärker.

Das Besondere an diesem Tag war aber die Entwicklung im oberen Teil der Gewitterwolke.

Es waren nicht nur die üblichen Fallstreifen unter der Wolke zu sehen, sondern es war ganz klar zu erkennen, dass der Regen auch aus den oberen Etagen in der Wolke fiel.

Es war tatsächlich ein Wasserfall im Himmel.

Das unbeständige Wetter dauerte an. Das Titelbild dieses Beitrages wurde ein paar Tage später, am 24. Mai, aufgenommen

In der Mitte Deutschland folgten im Mai weitere dramatische Ereignisse mit enormen Hagelmengen und Überflutungen an einigen Orten.

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A Waterfall In The Sky: Thunderstorms In May And Fallstripes

May is often a time in the year of short-lived thunderstorms and some cooler rainy days in Middle Europe. However, since some years there is also more severe weather with flash floods and even tornados in May. 2018 had been particularly unusual with new temperature records in April. It was too dry in many areas and it still is. A big problem is that it seems that steady rain is missing more and more. Long lasting rain was a common weather pattern every year which wasn’t very amusing for tourists but important for nature and farming. That changed. As predicted by climate change researchers we have more showers and thunderstorm with extreme flooding now.

When I was younger I remember May not as a very warm month. In some years there was still a lot of snow in the mountains. Often it was very cold in the middle of the month. But this year it was more like midsummer rather than spring.

In Southern Germany, the dry period ended to a certain extent and more and more showers and thunderstorms happened.

The first thunderstorm in my area close to lake Ammersee in Upper Bavaria developed on early evening May 12.

It was very impressing because of the late sun which illuminated the clouds and rain at a low angle. May is a good time for taking pictures of thunderstorms because often the light is better as in July and the air is often more clear. Furthermore, it is a good time to photograph fall stripes of rain which look like curtains and can create very interesting patterns.

The following days more thunderstorms occurred. Weather forecasters had a tough time during May. A couple of time stable, warm weather was predicted. But weather doesn’t behave like it was supposed to be. On Pentecost, May20+21, it should have been warm and dry but there were thunderstorms and showers. May 20 indeed was a surprise, because that “summer day” was more or less a dark day with a heavy thunderstorm and flooding in a village between Murnau and Garmisch Partenkirchen. Already on May 18 an open-air event had to be cancelled due to a thunderstorm in Fürstenfeldbruck, a city not far from Munich.




This is what Sunday, May 20, happened: In the afternoon the sky was loaded with dark clouds and rain. There were also shrouds of mist surrounding the Hohen Peissenberg, which can be seen in the background. Some lightning could be seen in the South. In the evening the weather calmed down.

Morning, May 21, began with a misty sky. There was a low hanging layer of mist between the mountains an the lower areas. The mist soon disappeared and the sky became clear:
The air was still humid and the sun was hot. Perfect conditions for the development of further thunderstorms. In the late afternoon, a thunderstorm cell moved towards lake Ammersee. It was very interesting to follow this thunderstorm since there were fascinating patterns of fall stripes. Furthermore, there was also a rainbow.

It was remarkable that this year in May the thunderstorms were often moving in unusual directions. Sometimes there were moving from South-East to South-West or from North to South. Mostly weather systems are moving from West to East. An unusual constellation of pressure systems in Europe was one reason for the long dry period and the further development.

The thunderstorm on May 21 was coming closer for some time but then stopped. Perhaps the huge lake had an influence. It happens often that lakes are influencing local weather.

In this case, it was again good to know some viewpoints in the area before. It made it easier to follow the weather pattern.

The higher position was particularly helpful to see the rainbow which developed during the thunderstorm.

The rainbow was barely visible for some time but then intensified.

However the most special thing was the development in the upper part of the thunderstorm-cloud.

There were not only fall stripes below the cloud but in this case, it was clearly visible that rain came from the upper levels.

It was indeed like a “waterfall” in the sky.

The unstable weather continued.The title picture was taken a few days later, May 24.

There were further dramatic events in the middle of Germany with flooding. There was also a tremendous portion of hail in some places.
KelbyOne. Get better at landscape photography.

Berlin, August 1, 2017: Spectacular Evening Sky

On August 1 again a hot air mass met a cold air mass over Germany. Subsequently, there was an air mass limit. Air mass limits are often the reason for severe weather events like extreme thunderstorms with tornados and flooding or downbursts.

(A good definition what an air mass is could be found at the UK met office:http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/air-masses.)

Severe storms were expected, the weather service also issued a warning for Berlin. In the afternoon and evening, a line of thunderstorms appeared. There was severe weather in Brandenburg and many other areas. However in Berlin after a short time of rain, the turbulent sky opened a bit and a red evening sun was illuminating the dramatically structured clouds.




Many people stopped and took pictures of the unusual weather situation. Of course, evening-glow happens a lot but this dramatic sky was extraordinary. One reason for this impressive sky is that if you have a weather situation with thunderstorms close or developing there is a chaos in the atmosphere. There are several levels in the lower and higher atmosphere with different clouds and there is a lot of circulation.

 

The impressive scenery lasted till it became dark. There was only a little wind and it was still very warm in the city during the night. Some sheet-lighting could be seen later but the bigger storms happened more in the South.

It was a relief after two severe storms with extraordinary flooding hit the city two times before.

But summer 2017 is very unpredictable in Europe. Two days later a very strong cell did damage in the South of Berlin and later in August Austria suffered from storms with heavy rain followed by mud-slides.

On the south-side of the Alps in Italy there are still heat-waves. As mentioned before these weather-patterns fit in the scenarios developed by scientists about effects of climate change.

 

There is a good-viewpoint between railway station “Gesundbrunnen” in Berlin and the well-known Bornholmer Straße. The pictures below were taken from a small bridge named “Schwedter Steig”. I had seen that bridge a couple of times when using the train. Its always useful particularly if you want to do weather-pictures to have an inventory of good view-points before, since if an interesting weather pattern occurs there is no time to search for a good place with a lot of open skies to take pictures or videos.

 

 

 

 

 

 

 

 

 

 

SHEET LIGHTNING: VIDEO BERLIN, AUGUST 28, 2016

Summer 2016 in Middle Europe: another year with new temperature records. August 28 was an extremely hot day in Berlin with temperatures over 34 C. Already the day before there had been some severe thunderstorms in Western Germany. A cold front was coming in from the west and in the afternoon the German Weather Service issued a warning for severe weather with strong wind gusts, thunderstorms and hail for Berlin and Brandenburg. However following nowcasts as provided by from some webpages showed that weather was very unpredictable that Sunday in Eastern Germany. It looked a couple of times as there were stronger thunderstorms taking course towards the East, then they lost their energy but in the evening some stronger storms appeared suddenly. Before the front arrived in Berlin the air became really hot and humid. It was sticky and the sky became overcast. In the south of Brandenburg there was already a strong thunderstorm. It was the typical scenario when you expect the worst. You could feel the tension.

Nevertheless there wasn’t a strong hit in Berlin, but a visually impressing storm system in the East of the City which generated sheet-lightning in the West. It was already nearly dark when that storm approached. Later, in the west side of the city there was only rainfall for some minutes. In other parts of Germany there were serious damages due to the collision between warm and cold air. There was a rotating supercell causing flooding in Hamburg and another storm did damage for example in Stendal. Lightning stopped trains in Hannover. The next day temperatures had dropped dramatically. In some places there was a temperature fall of 15 degrees. It was a release after these unusual hot days end of August. The learning lesson was that precise now-casts are still a difficult thing to do when there is chaos in the atmosphere, but should definitely further developed and made more popular since they could be a life-saving tool. Furthermore the trend of climate change related extremes continues in 2016. Adaption strategies seem mandatory for example for farming which suffered both from flooding and too much heat and droughts in other areas. It would be also worth to further investigate the connections between extreme weather and traffic accidents. Perhaps it’s a coincidence but there had been some accidents already before the thunderstorms arrived that day. Maybe the tension in the air, the humidity and the heat strongly affects the concentration of drivers. The situation in Berlin was worth for a little experiment with slow motion and an editing which created an effect similar to a time-lapse on the other side. Together with cross-dissolve transitions the video has perhaps a bit of a supernatural air:

Thunderstorm, Berlin 28. August 2016 from Peter Engelmann on Vimeo.