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A strong ridge brought exceptional warmth to large parts of Europe. In Germany, the unseasonably warm air mass led to many new temperature records for the first decade of April. The highest temperature was recorded in Ohlsbach, BW with a maximum temperature of 30.1 °C on April 06, 2024, marking the earliest recording of a 30 °C day in Germany.
While both February and March 2024 saw record-breaking monthly average temperatures, the beginning of April also saw above-average temperatures. In the first days of April, a strong ridge began to develop over Europe. The ridge led to the advection of exceptionally warm air masses from Northern Africa. 850 hPa temperatures rose up to 20 °C in Southern Germany.
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500 hPa Geopotential and sea surface pressure over Europe, 06.04.2024 00 UTC - 09.04.2024 12 UTC, source:
wetter3
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From an unorganized weak zonal structure which was present in the first days of April 2024, a strong trough over the Eastern North Atlantic led to a more meridional weather pattern across Europe. By Saturday, April 06, 2024, the surface low accompanied by the trough exacerbated the southerly flow over Europe as it neared the British Isles. As a result, the ridge over Europe was strongly amplified developing an omega pattern across Europe. With the main surface low of the trough moving into the Norwegian Sea, the ridge over Europe stretched eastwards into Western Russia. By Monday, April 08, 2024, a secondary surface low developed over Western Europe, quickly moving eastwards. With the surface low, the trough could move into Central Europe, shifting the warm air masses into Eastern Europe.
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850 hPa temperature over Europe, 06.04.2024 00 UTC - 09.04.2024 12 UTC, source:
wetter3
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On April 06, 2024, the temperatures in Germany reached unprecedented values for the first decade of April. Previously, the temperature record for the first decade of April was 27.7 °C. Especially in the western half of Germany, many weather stations recorded temperatures above the previous record. The highest temperature was recorded at Ohlsbach, BW, topping at 30.1 °C, setting the new record for the highest temperature recorded in the first decade of April. Furthermore, the recording at Ohlsbach, BW marked the earliest date a temperature above the 30 °C mark was recorded in Germany. The previous earliest temperature recording above 30 °C was on April 18, 2007.
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ICON-ART forecast for the mineral dust optical depth at 550 nm over Europe, 07.04.2024 18 UTC, source:
IMK-TRO
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Both on Sunday, April 07, 2024, and Monday, April 08, 2024, Saharan Dust reached Central Europe. Due to the dust over Germany, daytime maximum temperatures were slightly lower. This was a result of a direct reduction in solar radiation by scattering on the dust particles and an indirect reduction of solar radiation due to the dust particles acting as cloud condensation nuclei. With light precipitation over the western half of Germany, significant dust accumulations could be observed at the surface. Especially on darker-colored cars, the Saharan Dust was prominently visible, as seen in the attached pictures. Besides the washout of the Saharan Dust to the surface, the Saharan Dust also caused trouble in the German energy market as the current numerical weather prediction models often fail to resolve the radiative effect of Saharan Dust. As a result, a higher energy output was forecasted for PV systems in Germany than was observed.
3 day accumulated precipitation over Germany, 10.04.2024 00 UTC, source:
Wettergefahren Frühwarnung (left), and dust accumulated on a black car in Lahnstein, RP, 07.04.2024,
source: K.Gramlich
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In the eastern half of Germany, especially in Lusatia up to 4 consecutive days with daytime maximum temperatures above the 25 °C mark were recorded. Further south, in the southeastern part of France, extreme heat for April was observed with temperatures reaching up to 33.9 °C at Navarrenx in the departement Pyrenees-Atlantiques.
Text: KG
April 12, 2024
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