Since the start of the week, France has been in a situation of conflict between cool air descending from the British Islands and warmer and very unstable air rising from the Iberian Peninsula. Since Monday evening, the regions located between Nouvelle-Aquitaine, Pays de la Loire and Centre-Val de Loire have been the most affected by storms. These are accompanied in places by torrential rains, floods, hail and strong gusts.
Destructive hail in Médoc and Saint Emilion
A narrow corridor of hail hit part of the Médoc around 1 a.m. during the night from Monday to Tuesday as a line of particularly virulent storms passed through. The Naujac-sur-mer sector was hit hard with hailstones of around 5 centimeters. Around sixty homes suffered significant damage, according to an initial estimate. These disasters will be the subject of a request for transition to a state of natural disaster. This hailstorm was accompanied by violent gusts which caused damage.
During the night from Tuesday to Wednesday, the Libourne region and the Saint Emilion vineyard were in turn affected by severe hail storms causing damage to the vines.
A stationary storm with record rains in Mayenne
A stationary storm cell brought torrential rain to Cossé-le-Vivien in Mayenne, early Tuesday evening. In one hour, 107 mm fell, almost two months of rain. An intensity worthy of tropical regions, and record for this department in the north-west of France. This stationary storm was linked to a barometric marsh situation (little pressure gradient over a large geographical area) and to an air mass conflict, between the cool air which came down from the Channel, and the warm and humid which came up from the Bay of Biscay.
A tornado observed in Carlepont in Oise
Late Tuesday afternoon, a low-intensity tornado hit the Noyon region in Oise, more precisely the village of Carlepont. Roofs were damaged and a shed blown away by the strong wind, fortunately without causing any casualties. This tornado was linked to particularly unstable conditions in Picardy on Tuesday, with a wind at altitude different from that observed on the surface.
Flooding under the most intense storms, particularly in Gironde
Under the most active storms, the rains were particularly intense and caused runoff and mudslides in rural areas, with land that did not have time to absorb the precipitation. In the urban sector, the waterproofing of soils caused even greater runoff with volumes of water which saturated the drainage networks, and caused flooding in low areas. The town of Mérignac, on the outskirts of Bordeaux, suffered flooding in certain neighborhoods as a result of particularly intense stormy rains. 50 millimeters fell in one hour at the Bordeaux-Mérignac station, the equivalent of three weeks of rain.
The risk of sometimes violent thunderstorms will persist until the night of Thursday to Friday over a large part of the country. Consult our Special Press Release
