Europe will see a surge in slow-moving intense storms

The frequency of intense rainstorms will increase across Europe as a result of climate change, according to a new study led by Newcastle University. The experts predict that by the end of the century, slow-moving storms could become 14 times more frequent across land. 

The slow-moving storms will dump extremely high levels of precipitation, with the potential for devastating impacts like those caused by the recent storms in Germany and Belgium.

“This study shows that in addition to the intensification of rainfall with global warming, we can also expect a big increase in slow-moving storms which have the potential for high rainfall accumulations. This is very relevant to the recent flooding seen in Germany and Belgium, which highlights the devastating impacts of slow-moving storms,” said Professor Lizzie Kendon.

“Our finding that slow-moving intense rainstorms could be 14 times more frequent by the end of the century under the high emissions RCP8.5 scenario, shows the serious impacts that we may expect across Europe if we do not curb our emissions of greenhouse gases.”

For the investigation, a team of researchers led by Dr. Abdullah Kahraman used very detailed climate model simulations at the UK Met Office Hadley Centre. 

The results of the study indicate that the weather phenomenon is directly related to climate change, which is causing intense rainstorms to move more slowly. The experts found that the slower movement of storms will drive an increase in local rainfall accumulations, raising the risk of flash flooding across Europe beyond what was previously expected. 

“With recent advances in supercomputer power, we now have pan-European climate simulations resolving the atmosphere in high detail as short-range weather forecasting models do. These models have grid spacing of approximately 2 km, which allows them to simulate storm systems much better, resulting in better representation of extremes,” explained Dr. Kahraman.

“Using these state-of-the-art climate simulations, we have developed metrics to extract potential cases for heavy rainfall, and a smaller, almost-stationary subset of these cases with the potential for high rainfall accumulations. These metrics provide a holistic view of the problem, and help us understand which factors of the atmosphere contribute to heavy rainfall changes.”

“This is one of the first studies to explore changes in the speed of such heavy rainfall systems – an important aspect contributing to flood risk. Currently, we are also investigating other extreme weather types by examining the climate simulations data with a severe weather forecaster’s perspective.”

Professor Hayley Fowler pointed out that governments across the world have been too slow in reducing greenhouse gas emissions, and global warming is keeping pace. 

“This study suggests that changes to extreme storms will be significant and cause an increase in the frequency of devastating flooding across Europe,” said Professor Fowler.

“This, alongside the current floods in Europe, is the wake-up call we need to produce improved emergency warning and management systems, as well as implementing climate change safety factors into our infrastructure designs to make them more robust to these severe weather events.”

The study is published in the journal Geophysical Research Letters.

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By Chrissy Sexton, Earth.com Staff Writer