Intense, short-lived summer downpours are projected to become more frequent and intense in Alpine regions as temperatures rise. A recent study by researchers from the University of Lausanne (UNIL) and the University of Padova analyzed data from nearly 300 mountain weather stations, revealing that a 2°C temperature increase could lead to a doubling in the frequency of these extreme events.

In June 2018, Lausanne, Switzerland, experienced a severe rainfall episode, with 41 millimeters of rain falling in just 10 minutes, causing significant flooding and damage estimated at 32 million Swiss Francs.

Although these extreme events are currently rare in Switzerland, they are expected to become more common due to global warming, especially in the Alpine region.

Warmer air holds more moisture, intensifying thunderstorm activity. The Alpine region is particularly vulnerable as it warms faster than the global average, necessitating a thorough assessment of the impact of climate change in these areas.

The study, published in npj Climate and Atmospheric Science, indicates that a 2°C temperature rise could double the frequency of short-lived summer rainstorms in the Alps. An intense storm that occurs once every 50 years could happen every 25 years with such warming.

By analyzing data from weather stations across the European Alps, researchers developed a statistical model to link temperature and rainfall frequency, predicting future extreme precipitation events using regional climate projections.

Nadav Peleg, a researcher at UNIL and the study's lead author, emphasizes the significance of a 1°C temperature rise, warning of the potential for flash floods and infrastructure damage due to intense rainfall.

Francesco Marra, a researcher at UNIPD and co-author of the study, notes the likelihood of a 1°C temperature increase in the coming decades, highlighting the escalating trend of intensified summer storms.

Understanding the evolution of these events with climate change is crucial for implementing effective adaptation strategies, such as enhancing urban drainage systems to mitigate the impact of extreme rainfall.