This «strongly stormy situation at the end of summer requires particular vigilance» with in particular «a strong risk of a violent phenomenon», warns the forecasting institute, estimating that this alert should be lifted Thursday at 06:00.
The other departments in orange vigilance are Bouches-du-Rhône, Vaucluse, Gard, Hérault, Ardèche, Drôme, Isère, Loire, Haute-Loire, Rhône and Ain.
Wednesday morning, the strongest thunderstorms shifted off Provence and light showers were observed in the Gard foothills and in the Rhône valley, specifies Météo-France.
But stormy recoveries are expected in the afternoon. At the end of the day and next night the stormy line should sweep from west to east the Hérault, the Gard and the Rhône-Alpes region before shifting towards the Var and the Alpes-de-Haute-Provence in the middle of the night. .
These storms should be accompanied by strong electrical activity, with hail in places and gusts of up to 100 km / h. 40 to 60 mm of additional rain could fall, or even more in the Cévennes and in the Rhône valley. Cumulative precipitation could occasionally reach 130 mm in Hérault, Vaucluse and Gard, which had been placed on red alert for a few hours overnight from Tuesday to Wednesday.
“The Nîmes urban area was hit by a violent storm overnight, with up to 135 millimeters of rain,” a spokesperson for the Gard fire department told AFP on Wednesday morning.
Faced with these downpours, the emergency services carried out «fifteen safety measures» for motorists who were temporarily welcomed into a gymnasium. The firefighters had also carried out about fifty minor interventions (manhole covers raised by the waters, etc.), always in the region of Nîmes.
Gard and Hérault had already been placed on red alert on Tuesday afternoon for three hours, due to stationary thunderstorms.
This level of absolute vigilance is activated in the event of «very violent storms, likely to locally cause very significant damage», in particular «on dwellings, parks, crops and plantations», explains Météo France.