In a new bulletin, Météo-France places 28 departments in a large western half of the country on orange alert for thunderstorms for the evening of Sunday, September 17. An “intense” episode is expected with hail, gusts of wind and heavy rain in places.
“We will have storms which will start to form from New Aquitaine during the afternoon. They will go up to Normandy until the middle/end of the night, passing through Centre-Val de Loire and Ile-de-France,” Tristan Amm, forecaster at Météo-France, described to AFP. .
“These will be intense thunderstorms. We can expect hail, significant lightning strikes, wind gusts that can exceed 100 km/h, and rain that can seem torrential, quite brief most of the time,” he said. added. Météo-France anticipates precipitation of up to 40 mm/hour. The national meteorological institute had placed 33 departments on orange alert on Sunday, from New Aquitaine to Normandy via Ile-de-France. There were still 28 left after 8 p.m.
But France will not yet be finished with storms. “The situation is unstable across the entire country which is affected by a mass of warm and humid air very conducive to the formation of thunderstorms”, when the hot air “butts up with the colder air above” , explained Tristan Amm.
“From the end of the night from Sunday to Monday and during the day on Monday, a new rainy-stormy episode will affect the east of the Cévennes as far as the Drôme. Heavy stormy precipitation in a short time is likely,” specifies Météo-France, which expects cumulative rainfall of “80 to 100mm.”
On Saturday, the Hérault department, placed on red alert for rain and floods, was affected by very heavy rainfall, leading to the closure of a railway line, while several roads were cut. This episode notably caused flooding in the town of Lunas, in the north of the department, where the flood of the Orb swept away “several cars” and flooded “several houses in a hamlet located on the edge of the river”, without causing any casualties, the mayor of the town, Aurélien Manenc, who is also a firefighter, testified to AFP.
In Mayenne, a mini-tornado formed on Sunday, around 6 p.m., near Ernée, damaging several buildings which collapsed without causing any casualties, we learned from Codis.
Temperatures remained well above seasonal norms on Sunday, while France last week beat its temperature record for a month of September, which dated from 1949.