Expectations were high before this Sunday: summer must finally arrive! This year, Bavarians aim and expect 27, even 29 degrees, which has not been achieved so far. Instead: cloudy weather from Upper Bavaria to Lower Franconia in the morning, 16 degrees in Kempten, 18 degrees in Weiden in der Oberpfalz. Only in the afternoon did the cloud field clear in many places in the east and temperatures rose to 26 degrees in Lower Franconia.
Dust particles favor the formation of clouds
The killjoy was called: dust from the Sahara. Due to the strong development of low pressure in the Mediterranean area – climate expert Stefan Ochs from Herzogenaurach speaks of a “storm that raised a lot of dust in the Sahara” – a good load of dust from the Sahara reached Central Europe and not only in Bavaria, but in distant parts of Central Europe clouded the consistently sunny outlook. Sometimes there were up to 1,500 mg/m² of Saharan dust over our heads – for the Bavarian area, about 75,000-100,000 tons of Saharan dust. Dust aerosols, i.e. tiny particles floating in the atmosphere, convert very humid air into clouds. This destroys the meteorologists’ summer forecast.
Sahara dust: a challenge for weather forecasting
Correctly assessing climatic conditions with Sahara dust is very difficult for meteorologists and climate researchers. They know that Saharan dust promotes clouds, but the models they work with fail to adequately capture the phenomenon. That’s why, even now, some weather apps still claim that the sun is shining in the sky.
Monday will likely look like Sunday
A similar game is indicated for tomorrow, Monday: The models continue to show a lot of sun and at most some fields of high and thin clouds. But there is also a similar amount of Saharan dust in the air. BR weather expert Christian Lorenz therefore corrects his forecast to “fairly friendly with some clouds”. He deliberately remains somewhat inaccurate, because Saharan dust is “unpredictable”. If there are individual showers or thunderstorms on Sunday or Monday, the dust from the Sahara will be washed away at least locally and can – if it doesn’t rain heavily – be seen on window sills, garden furniture and cars.
Rain on Tuesday – and some hope for today’s Sunday
Showers and thunderstorms are likely to partially wash away the dust from the Sahara on Tuesday. However, a forecast from the University of Athens also shows dust from the Sahara in Bavaria for Wednesday night through Friday – albeit in small amounts.
And today’s Sunday – can it still be saved? In Swabia, Upper and Lower Franconia, the sun peaks through cloud cover in places. If you manage to do this further, the clouds may dissolve due to heatstroke. And with temperatures around 20 degrees, you can certainly get something started with the day.