Météo France has placed the departments of Hérault and Gard under red alert for heavy rain and flooding for Wednesday, September 30, warning of an “exceptional Mediterranean rain and thunderstorm episode” requiring particular attention due to remarkable and widespread rainfall intensities and accumulations.
The alert came into effect at 8 a.m. and is expected to remain in place throughout the day. Lozère and Ardèche remain under orange alert, with Bouches-du-Rhône to be elevated to the same level from midday.
Rainfall Intensifying Across the Region
In its 6 a.m. bulletin, Météo France reported that precipitation rising from the Mediterranean and becoming blocked over the Cévennes mountains and their foothills had strengthened, particularly in the Hérault department and the Viganais Cévennes area.
Between 3 a.m. and 6 a.m., rainfall accumulation reached 114mm in the commune of Moulés-et-Baucels, with totals ranging from 15 to 30mm in the lower Hérault plain and 70 to 100mm in the Viganais Cévennes. As rains “significantly strengthened at the end of the night,” the weather episode is expected to intensify further on Wednesday, justifying the red alert.
On the relief and Cévenol piedmont, rainfall intensities are expected to be particularly marked, with 50 to 80mm possible in a single hour, according to Météo France, which anticipates accumulations approaching 200 to 250mm.
In the plains, “strong intensities of around 60 to 100mm per hour may be observed.”
Major Flooding Expected
Météo France also warned of “significant flooding to come on the Gardons d’Alès and d’Anduze, the upper Cèze and upper Hérault” rivers.
Vigicrues, the national flood monitoring service, has placed the Gard department under orange alert, corresponding to a “risk of flooding capable of causing significant overflow.”
“The intense precipitation currently occurring over the Gard Cévennes will persist throughout the morning, causing marked reactions in watercourses during the same period. Damaging overflows may be observed,” the agency stated, warning that the situation could evolve during the day.
Transport Disruptions and Safety Measures
The weather episode has forced a “total interruption” of rail traffic on Wednesday along the Nîmes–Alès–La Bastide–Marvejols–Clermont-Ferrand line, SNCF announced overnight, adding that replacement buses would be provided.
In Gard, the prefect has suspended all school transport for the entire day, with the prefecture highlighting particular flood risks from several watercourses.
The Hérault prefecture warned of “very high-intensity thunderstorms” and reminded residents of safety guidelines:
- Postpone travel
- Do not enter basements or underground areas
- Stay away from watercourses
- Never attempt to cross a flooded road on foot or by vehicle
School transport has also been suspended in eight of the department’s 14 sectors.
