The warning came from Christophe Béchu, Minister of Ecological Transition, as he launched the government’s seventh life-saving seasonal storm awareness campaign.
The risk this year is such that the annual campaign – which targets 15 départements in the south of the country – has been extended until November 30th. Previous years’ schemes have ended on October 31st.
“Unfortunately, all the climatic conditions are set so that we find ourselves again this year with very violent phenomena [in the autumn],” Christophe Béchu, Minister of Ecological Transition, announced on Tuesday.
Weather experts and climate scientists have already warned that violent and sometimes deadly storms – known as épisodes cévenol or épisodes méditerranéen – are likely to be more intense this year because the Mediterranean sea is several degrees warmer than usual.
Abnormally high temperatures in the Mediterranean Sea, three to five degrees above normal, means that “the warmer the Mediterranean, the more water evaporates, the more it goes into the sky and the more potential it has to lead to very heavy rainfall,” Christophe Person, head of BFMTV’s weather desk, explained.
Meanwhile, the historic drought in France this summer means that the ground is parched, which means water will not soak into the ground – as this experiment demonstrates – and therefore makes flash flooding much more likely.
In this experiment Dr Rob Thompson of @UniRdg_Met shows just how long it takes water to soak into parched ground, illustrating why heavy rainfall after a #drought can be dangerous and might lead to flashfloods. @R0b1et @UniRdg_water pic.twitter.com/zbb3xLTXdK
— Uni of Reading (@UniofReading) August 10, 2022
Météo-France reported on its website in early August that, “at the national level, since July 17th, France set a new record of soil drought every day” – adding that the conditions are worst in the south of the country.
“The soils are so dry, the temperatures are so high, that it can promote phenomena of diluvian floods that cause up to 200 litres of water per square meter and can be dramatic for the inhabitants,” Béchu said, as he warned residents of 15 départements along the Mediterranean arc to be alert to the risks of flooding and landslides.
The 15 départements on high alert this autumn are: Alpes de-Haute-Provence, Alpes-Maritimes, Ardèche, Aveyron, Aude, Bouches-du-Rhône, Corse-du-Sud, Haute-Corse, Drôme, Gard, Hérault, Lozère, Pyrénées-Orientales, Var and Vaucluse.
They are home to some 9.1 million people, who are advised to pay close attention to weather reports Meteo France, including its weather alerts system, and flood warnings from Vigicrues – and be aware of the appropriate action to take in case of storms.