The heavy rainfall was sustained by a stalled low-pressure storm system that became cut off from the jet stream, also understood as a cut-off low. Central Greece was among the hardest struck by the storm in terms of rains, with record quantities falling on the Thessaly region on September 5. The greatest levels of rainfall, 754 millimeters (30 inches), fell on Zagora, a village near Mount Pelion, simply northeast of Volos. The map at the top of this short article portrays a satellite-based price quote of rainfall rates (in millimeters per hour) over Greece for September 6, as heavy rain continued. The darkest reds show the greatest rainfall rates, which again hit Central Greece as well as areas to the south, including Athens.
Effect in Greece
Central Greece was among the hardest struck by the storm in terms of rains, with record amounts falling on the Thessaly area on September 5. The greatest levels of rains, 754 millimeters (30 inches), fell on Zagora, a village near Mount Pelion, simply northeast of Volos. For contrast, the capital city of Athens gets an average of about 400 millimeters (16 inches) in a year. The Krafsidonas River, which comes from Mount Pelion, broke its banks in Volos and ruined a bridge in its path.
Satellite Data on Rainfall
The map at the top of this article portrays a satellite-based estimate of rainfall rates (in millimeters per hour) over Greece for September 6, as heavy rain continued. The darkest reds reflect the highest rains rates, which again hit Central Greece along with areas to the south, consisting of Athens. The data are from another location picked up estimates that originate from the Integrated Multi-Satellite Retrievals for GPM (IMERG), an item of the Global Precipitation Measurement (GPM) satellite mission. Due to averaging of the satellite data, regional rainfall rates might be substantially higher when determined from the ground.
Flooded Comparisons and areas
Using satellite information from the European Space Agencys Sentinel-1 satellite, Meteo reported that since September 6, big parts of Thessaly had actually been flooded. On that day, 331 millimeters (13 inches) fell on the city of Karditsa, which has to do with 100 kilometers (60 miles) inland from Volos. Athens got 55 millimeters (2 inches) of rain, according to Meteo.
Extent of Flooding in Neighboring Regions
The very same low-pressure system produced deadly flooding in eastern Bulgaria and western Turkey on September 5, however eased by the next day. In Greece, the storm gradually receded by the evening of September 7.
A few of Meteos meteorological stations stopped sending due to power failures, however over the four-day storm, they tape-recorded the most cumulative rain over the Thessaly area. Zagora saw 910 millimeters (36 inches), and 659 millimeters (26 inches) fell on Karditsa.
NASA Earth Observatory image by Lauren Dauphin, using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC.
Satellite-based estimate of rains rates (in millimeters per hour) over Greece on September 6, 2023.
A stalled storm dropped three feet of rain over 4 days on the Thessaly area, activating extensive flooding.
Following weeks of heat waves and fires, torrential rains unleashed widespread flooding in Central Greece in early September 2023. Throughout the four-day storm that began on September 4, floodwater submerged homes, turned streets into raging rivers, and swept automobiles out to sea.
Reasons for the Heavy Rainfall
The heavy rains was sustained by a stalled low-pressure storm system that ended up being cut off from the jet stream, also understood as a cut-off low. This storm was comparable in nature to the cut-off low that caused downpours in Spain on September 3, and belongs to an uncommon omega weather condition system, in which a zone of high pressure is sandwiched between 2 areas of low pressure. This omega weather condition system was blamed for both an unseasonal heatwave in the UK and the catastrophic flooding in Spain, Greece, Bulgaria, and Turkey.
