Heavy rains in Odesa: meteorologists explained the causes and impact of climate change
Kyiv • UNN
On September 30, Odesa received 94 mm of precipitation, which is more than 220% of the monthly norm, caused by a local cyclone and climate change. Extreme precipitation is becoming more frequent due to the warming of the Black Sea and urbanization, which exacerbates flooding.
On Monday, September 30, Odesa was covered by heavy rains, which became some of the most intense in recent years. According to the weather station, 94 mm of precipitation fell in 24 hours – this is more than 220% of the monthly norm. Previous records fell on September 20, 2016, when 113 mm fell in 24 hours. The Ukrainian Hydrometeorological Center explained the reasons for such bad weather, writes UNN.
Details
As explained by forecasters of the Ukrainian Hydrometeorological Center, heavy precipitation was the result of a local cyclone over the Black Sea, the movement of which to the north and east was blocked by an anticyclone. This led to the activation of atmospheric fronts. Additionally, the intensity of the rain was increased by warm and humid air over the sea.
Forecasters of the Hydrometeorological Center of the Black and Azov Seas warned of the threat: significant rains were expected on September 30 from September 29 (yellow level), and on September 30 at 3:30 p.m. the warning was strengthened to the second orange level (precipitation amount 50–79 mm until the end of the day), at 7 p.m. — to the third red level (over 80 mm)
Forecasters emphasize that extreme precipitation in Odesa is becoming more frequent due to climate change. Over the past 10 years, 14 cases of heavy rain in a short period of time have been recorded in the city, while in previous decades, similar phenomena occurred 2–3 times in 10 years.
The reasons for more frequent heavy rains are related to the warming of the Black Sea surface, the activation of convection processes, and increased atmospheric humidity. Similar phenomena, such as rainbands, previously typical for the tropics, are now appearing in mid-latitudes, forming at the border of water areas and land. They can mask cold fronts and provoke local catastrophic precipitation.
Urbanization further increases the risks of flooding: asphalt and concrete do not let water through, which turns rain into strong currents. Studies in the US and UK show that in densely built-up cities, runoff volumes increase by 20–50%. Forecasters advise adapting cities through "green" infrastructure – the use of porous coatings and the creation of green areas can reduce flooding by about a third.
Recall
In Odesa and the district, work is underway for almost a day to eliminate the consequences of bad weather. According to the State Emergency Service and the Odesa City Council, 9 people died as a result of heavy rains, including a child. Pumping stations were flooded, traffic was restricted, and changes were made to public transport routes.
President of Ukraine Volodymyr Zelenskyy stated that he had instructed to conduct a full inspection due to the death of nine people in Odesa during bad weather and to prepare a corresponding report this week.
In Odesa region, October 2 was declared a Day of Mourning due to the death of nine people during bad weather in Odesa. Among the dead, five were members of the same family, including a child.