Storm Ciaran, which hit western Brittany then Cotentin during the night from Wednesday November 1 to Thursday November 2, with record gusts of wind, will begin to slide towards the west of the countries of the Loire and go further into Normandy. Only limited damage has been reported so far and one minor injury has been reported in Finistère, in Plouédern, following a traffic accident caused by a falling tree, the prefecture said.
Three departments in the North-West have gradually entered wind-red vigilance since midnight: Finistère at midnight, Côtes-d’Armor at 2 a.m., then Manche an hour later. Only the last two remain on red alert Thursday morning.
Numerous tree falls have led to the temporary closure of certain major roads, notably the RN12 in Côtes-d’Armor, and the RN165 in Morbihan. Power cuts were also recorded in several departments, including Finistère, Morbihan and Manche.
Traffic prohibited in Finistère
Traffic was prohibited Thursday morning on the entire road network in Finistère, the prefecture indicated, the storm having caused “many trees, branches and electrical and telephone lines to fall to the ground.” This ban concerns “the entire departmental road network (local, municipal, departmental and national roads)”, notes the prefecture.
This ban will be lifted gradually “as the clearance operations progress, for which all very important resources are mobilized,” adds the prefecture.
In Finistère, Météo-France recorded, around 3 a.m., 193 km/h in Plougonvelin, where Pointe Saint-Mathieu is located, 171 km/h in Lanvéoc, on the Crozon peninsula, and 156 km/h in Brest. “The wind gusts are exceptional over Brittany and many absolute records are broken” locally, indicates Météo-France on X (formerly Twitter). In Morbihan, the prefecture indicated that gusts reached 164 km/h on the island of Groix, 152 km/h in Belle-Ile and 147 km/h in Lorient.
“Gusts exceeding 100 km/h extend from Vendée to the west of Calvados via Sarthe. At the stations of the Atlantic arc and the western side of the Manche department, we observed gusts of around 150 km/h to 170 km/h or even more on the exposed semaphores,” Météo-France further explains.
Planes in difficulty and diverted
Orange “wave-submersion” vigilance is now activated for the coastlines of Finistère, Morbihan, Loire-Atlantique and Vendée, specifies Météo-France. Waves of eight to ten meters are expected on part of the Atlantic coast.
The number of departments placed on orange vigilance, for “waves-submersion”, “wind” or “rain-flood”, is thirty-one. Among the new departments classified in orange are part of those in Ile-de-France, including Paris, for violent winds. The entire coastline from Pas-de-Calais to the Pyrénées-Atlantique is now on orange “wave-submersion” alert for Thursday, as are Bouches-du-Rhône, Var and Alpes-Maritimes. Southern Corsica is also on orange alert for “thunderstorms” as well as “rain-flooding”.
According to Ouest-France, planes in difficulty above Nantes airport in the evening due to winds were finally diverted to Toulouse. Almost everywhere on the coast, calls for caution, particularly for walkers and boaters, have increased. These submersion waves are particularly devastating on the coasts where careless walkers are regularly swept away.
Due in particular to the risk of falling trees due to violent winds, the transport sector will operate slowly on Thursday in the west of the country. “On the road front, we have taken measures via the prefectures to ban the circulation of heavy goods vehicles (…) This will be effective during the day of Thursday, particularly throughout the Brittany region,” said the Minister for Transport, Clément Beaune. The Ministry of the Interior then clarified that Ille-et-Vilaine, on orange alert, was ultimately not affected by this traffic ban. As for Brest and Quimper airports, “they will not be in service between the end of the afternoon and at least the morning of tomorrow,” he added.
Météo-France is concerned about a “heavy rainy episode”
The SNCF announced that it was planning, on Thursday morning, “preventive stops of rail traffic” on part of the RER A, on several Transilien lines (L, J, U and partially N) and for the T13 tram. .
For trains, TER traffic in Brittany, Normandy, Hauts-de-France, Pays de la Loire and Centre-Val de Loire was interrupted from Wednesday evening to Friday morning. As for the TGVs, if 90% of them are expected to circulate, traffic will be interrupted on the Paris-Le Mans and Paris-Nantes axes.
In addition to the winds, Météo-France is concerned about a “rainy episode giving significant amounts of precipitation in a short time on already saturated soils”, with in particular possible falls of trees that are still very leafy for the season.
Extreme weather events (cyclones, heatwaves, floods, droughts, etc.) are natural phenomena. But global warming caused by greenhouse gas emissions generated by human activity can amplify them.
Concerning more specifically the phenomena of submergence waves on the coasts, these risk becoming more dangerous with the rise in sea level linked to the melting of the ice, particularly during storms.
The President of the Republic, Emmanuel Macron, joined the numerous messages from the authorities on Wednesday evening urging caution in the face of this climatic event. “Don’t take a chance. Stay at home and check on your isolated loved ones,” he wrote on social media.
