An Omega block has dominated the European weather status this week, leading to significant and varied impacts across the continent.
This meteorological phenomenon, characterized by a high-pressure region flanked by two low-pressure areas, has created a stable yet extreme weather pattern.
The setup, resembling the Greek letter omega, has brought a mix of intense rainfall, thunderstorms, and unusually high temperatures to various regions.
In Greece, Storm Daniel emerged over the Ionian Sea, fueled by the warm waters and the influence of the Omega block. As the storm moved inland on Monday, September 4th, it unleashed torrential rain and severe thunderstorms, particularly across central Greece.
The region experienced its heaviest rainfall in nearly two decades, with some areas receiving more than half a meter of rain within 24 hours.
Omega block traps heat and rain across Europe, triggering extreme weather from Greece to Spain.Notably, a weather station in Zagora, on the Pelion peninsula, recorded an astonishing 754mm of rain, breaking the previous record of 644.7mm set in September 2020 in Paliki, Cephalonia.
To put this into perspective, the nearby city of Volos typically sees 802mm of rain annually, meaning nearly a year’s worth of precipitation fell in a single day.
The storm’s devastation has been widespread, with 11 deaths reported across Greece, Turkey, and Bulgaria. Landslides have also been triggered, particularly on the Greek island of Skiathos, further highlighting the destructive power of Storm Daniel.
Meanwhile, Spain has not been spared from the adverse weather. A cutoff low-pressure system, detached from the main atmospheric flow, has caused severe rainfall in the western Mediterranean.
Madrid was placed under a red alert for rainfall as thunderstorms battered the region on Monday, leading to rivers overflowing, street flooding, and the temporary shutdown of the metro system.
In Mas de Barberans, Catalonia, 240mm of rain fell in just 24 hours on September 2nd, marking the highest rainfall total there in 23 years.
Across central and northern Europe, including the UK, temperatures have soared, ranging between 5°C and 10°C above the seasonal average.
This unusual warmth is expected to persist through the weekend and into the following week, adding to the region’s list of extreme weather events.