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Extreme flood in Russia kills 171

By: Dr. Jeff Masters, 1:14 PM GMT on July 09, 2012

Earth's deadliest flood of 2012 hit the Black Sea area of Russia on Saturday, where 300 mm (11.8") of rain fell in less than 24 hours. The resulting flood waters swept through the town of Krymsk in the Krasnodar region early Saturday, killing at least 171 people. The heavy rains were caused by a low pressure system that tracked just north of the region. The counter-clockwise flow of air around the low brought moisture-laden air from the Black Sea northwards over the mountains bordering the Black Sea. As the air was forced upwards by the mountains, its water vapor cooled and condensed into heavy rains. The rains were increased due to ocean temperatures in the Eastern Black Sea that were more than 2°C (3.6°F) above average. The extra heat in the ocean allowed much more water vapor than usual to evaporate into the air. Rare 1-in-20 year heavy precipitation events like the one that caused the Krasnodar flood are expected to increase in frequency due to climate change, as the waters of the Black Sea warm. According to the 2011 Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX), issued by the United Nations Intergovernmental Panel on Climate Change (IPCC), 1-in-20 year extreme precipitation events are likely to occur with a 1-in-11 to 1-in-15 year frequency by the year 2100 in the Black Sea area of Russia. A warmer atmosphere holds more water vapor, increasing the odds of very heavy precipitation events.

Figure 1. Flood damage in Krymsk, Russia, from Saturday's deadly flood. Image credit: Associated Press.

Figure 1. True-color satellite image of Russia's Krasnodar region along the northeast coast of the Black Sea, taken at 09:30 UTC Friday, July 6, 2012. The counter-clockwise flow of air around a spiraling low pressure system centered just north of the region was bringing a flow or moisture-laden air from the Black Sea over the city of Krymsk. Image credit: NASA.

Quiet in the Atlantic
There are no threat areas to discuss in the Atlantic, and none of the reliable computer models are developing a tropical cyclone over the next seven days.

I'll be back this afternoon with a full wrap-up on the remarkable heat wave of 2012.

Jeff Masters


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