This Tuesday between 10 a.m. and 1 p.m. Tuesday, incessant and very impressive rain accompanied by thunderclaps fell on the Brittany center and on Loudéac. The stormy conditions had been announced by Météo France but probably not with so much precipitation. Roads were flooded on Loudéac, with evacuations of rainwater that could no longer keep the infernal pace. Lightning and thunderstorms also caused microcoupures of electricity all morning.
On the RN164 which crosses all of Center-Brittany, the road was sometimes difficult to pass with a significant risk of aquaplaning. Around 11:30 a.m., an accident took place near Saint-Caradec between two vehicles.
Up to 90 millimeters of precipitation in three hours in Plœuc-l’Hermitage
In terms of precipitation, according to Steven Tual, meteorologist, he fell 80 millimeters of rain in the space of three hours west of Loudéac, 50 millimeters at the city of Center-Brittany and 90 millimeters towards Plœuc-l’Hermitage. For comparison, rainfall was 684 millimeters in the year 2024 in Loudéac. “It is a stationary storm caused by a cold drop that the Brittany center knew,” he explains. The cold drop is a cold air pocket at altitude faced with hot air on the ground. Here, the hot air came from the south, on the side of Redon, when the fresh air came from the north, from the Goëlo coast ”.
Strong stormy activity and many lightning impacts
Another exceptional phenomenon, the number of lightning impacts broke records in the Côtes-d’Armor department, with 780 counted, at 2:15 p.m. on Tuesday. “It is however the least struck French department in France in normal times,” says Stéven Tual. Only on Loudéac, 204 lightnings were recorded in the space of three hours.