Watch out for the flood. Seven departments of the Mediterranean arc were on orange alert overnight from Tuesday to Wednesday due to the risk of potentially violent thunderstorms, Météo-France particularly fearing stationary thunderstorms, which could lead to heavy accumulations of rain. Around midnight, no damage had been observed, and Météo-France had even lifted vigilance on the Aude earlier in the evening.
In the Hérault, where strong thunderstorms had started in the evening, the rain was very sustained without causing overflows, according to the firefighters, who however remained mobilized for the night. Météo-France has predicted locally violent summer storms, without for the time being qualifying the episode as “Mediterranean”.
The 100 mm probably exceeded
“The Mediterranean episode is when we start to have stationary cells which give strong accumulations of rain (…) from thresholds of 100 mm locally”, explained during a press briefing Frédéric Nathan, forecaster for Météo-France, describing the current episode as “fairly classic”. “A stormy summer episode, which we have already experienced in the past: August 9, 2018, in 2006, in 2010 in June…”, he added. In its last bulletin, Météo-France predicted “a risk of violent phenomena”.
In the Hérault as in the Gard, Météo-France expects “very high” rainfall intensities, which can reach 80 mm in a very short time: “We can locally exceed 100 to 130 mm under stationary storms”. In the Gard, as a precaution, the prefecture has recommended that campsites evacuate their customers. “Most have chosen to shelter, in their rooms + hard +, campers in tents or caravans,” the prefecture told AFP.
The Gard firefighters announced on Tuesday afternoon that they had reinforced all the barracks and had positioned three multipurpose flood groups on the ground. After 2 a.m., the Vaucluse, the Bouches-du-Rhône and the Var will be hit by storms. Like Hérault and Gard, these departments are placed on yellow alert for flood risks.
The Var affected Wednesday morning
In the Var on Wednesday morning, thunderstorms may be associated with strong gusts of wind and vortex phenomena. “After a few hours of calm, a new, very stormy episode will take place from Languedoc to Provence”, also informed Météo-France.
The Var firefighters announced that they were alerting “additional resources” including “six units of whitewater rescuers” on Wednesday.
The departments of the Mediterranean arc have all experienced floods in the past with sometimes dramatic consequences. In Vaison-la-Romaine (Vaucluse) in 1992, sudden and violent rains washed away part of the town and killed 37 people, the deadliest floods France has ever known.
Finally, in the fall of 2020, a deluge of water in the Alpes-Maritimes caused exceptional floods which carried away entire sections of the Vésubie and Roya valleys in their path. A tragedy that left ten dead, eight missing and two billion euros in damage.