Météo-France has placed eleven departments in vigilance orange thunderstorms and rain-flooding and strong winds, anticipating an intense Mediterranean episode in the south of France for Friday night and Saturday.
In its 16-hour bulletin, Météo France judged that the current episode required "special monitoring because of its intensity and duration" in 11 departments, against five announced earlier in the day. In addition to the Ardèche, Gard, Herault, Gard and Lozere, Météo France also fears heavy rains and thunderstorms in the Alpes-Maritimes, the Bouches-du-Rhone, and strong winds in Drôme, Isère and Loire. The Aveyron is concerned by a flood warning.
Up to 15 mm of rain Friday afternoon on the Cevennes
Friday afternoon, already, the precipitation continues on the Cevennes, with accumulations observed from 5 to 15 mm in three hours. On the Var, "the rains or showers multiply, giving locally more than 10 mm per hour". It is on this department that the risk is the greatest with accumulations expected between 120 and 150 mm, 180 to 250 mm locally. These storms, sometimes accompanied by hail and strong gusts, may also give rise to swirling phenomena near the coast. The most intense rainfall will occur in the morning Saturday, alerted the prefect of the Var.
Strong winds expected on Saint-Étienne
These rains on the south of the Massif Central as well as on the Paca region, "will generate significant floods", forecasts Météo France. Precipitation will be aggravated by a strong wind near the coast and in the mountains, giving "strong waves of south-east sector combined with high water levels". In the Rhône-Alpes, the southeast wind will continue to strengthen in the coming hours, and will reach 100 to 120 km / h on the Ardèche plateau and the heights of Pilat, and more than 100 km / h possible on the agglomeration from Saint Etienne and the Gier valley down to Givors.
"This wind can also affect areas of plain where structures have already been weakened by the snowfall last week," warns Météo France. Nearly 1,000 homes were still without power in the Drôme Friday, after the heavy snowfall of the previous weekend.