St. Martin Vesubie Flood Damage – August 2024 Update

On Oct 2 and 3 2020, Storm Alex, a powerful early-season cyclone, dropped about 500 milliliters of rain on Saint-Martin-Vésubie, a mountain town about 65 kilometers north of Nice, in just over 24 hours.

How much rain is that?

As France 24 reported, “Meteo France said that rainfall of 500 mm (19.69 inches) of rain was registered over 24 hours in Saint-Martin-Vésubie and close to 400 mm in several other towns – the equivalent of more than three months of rain at this time of the year.”

The ensuing intense floods washed away dozens of kilometres of roads and bridges and damaged or destroyed hundreds of buildings. Eighteen people were killed. It was a once-in-1000 years weather event, the worst and most destructive flooding in southeast France in at least 120 years, since record-keeping began. (The Guardian has a good gallery of the storm’s immediate aftermath.)

Above and below are a few images that show how rebuilding is coming along nearly four years later. It’s a good illustration of how long damage from extreme weather events lingers – long after the handful of hours or couple of days the event is in the headlines. The storm claimed 20 lives and pounded the region with more than €2.5 billion in damages.

A 2022 study by the Climate and Environment Sciences Laboratory looked into how impacts of climate change might have fuelled the storm. The research, ‘A methodology for attributing severe extratropical cyclones to climate change based on reanalysis data: the case study of storm Alex 2020’, uses:

… climate observations of the last seven decades to define two different climate periods: a past period from 1950 to 1984, and a more recent period, from 1986 to 2021. The latter represents a climate largely influenced by anthropogenic emissions, while in the former, the human influence on climate is weaker. They first identified 30 storms similar to Alex, which they named analogues, by selecting those that resemble Alex in terms of sea level pressure in each period. They then compared the characteristics of the storms of the past and present periods. They found that Alex-like storms in the more recent period have more meridional atmospheric pressure patterns, and they are more persistent. Storms in the present period become more common in autumn, when Alex took place. In terms of impacts, there is an increase in precipitation and wind gusts in Southern France and Northern Italy, increasing the probability of severe flooding events. Therefore, those changes collectively point to Alex-like storms more impactful and common in a warmer climate.

More from the study.

Photos from 16 August 2024