Weather Alert: Risk of strong thunderstorms and hail in the southwest

From Sunday May 19 at 12:00 to Tuesday May 21 at 9:00.

Situation

France is in a depression context with a cold drop over the near Atlantic. Until Monday, a fairly marked rainy and stormy deterioration is in place from Midi-Pyrénées to the Aquitaine basin to the west of the Massif Central. Rainfall accumulations can reach nearly 40 mm locally in just 1 to 2 hours, which represents two weeks of precipitation. The risk of stormy phenomena should mainly concern the extreme southwest with a localized risk of hail and strong gusts (70 to 80 km/h) in the south of Aquitaine and the Pyrenean foothills until Sunday evening 23 h.

Observation

This Sunday

At 3 p.m., heavy stormy showers move up from Midi-Pyrénées towards the center of Aquitaine in connection with the rise of the Spanish depression towards the Bay of Biscay.

At 12, with the rise of the disturbance in Spain driven by the cold drop present on the Bay of Biscay, stormy rains settled over the south and center of Aquitaine. Since 6 a.m. this morning, an average of 5 to 10 mm has already fallen from the Pyrénées-Atlantiques to the Gironde.

At 09 h, the weather is already unstable in the southwest with showers, which for the moment have not yet taken on a stormy character.

Evolution

This afternoon
Ahead of the disturbance coming up from Spain, sometimes strong thunderstorms are developing near the Pyrenees to the south of Aquitaine with heavy accumulations of rain.

This evening
Stormy showers are spreading from the Pyrenees to the center of Aquitaine and progressing towards Limousin with potentially strong phenomena.

Night from Sunday to Monday
The disturbance persists in the southwest with a marked rainy character. Accumulations of more than 20 to 40 mm are still possible throughout the night in the Aquitaine departments while storms are quickly losing strength in Midi-Pyrénées and Limousin.

Monday morning
The disturbance continues to the southwest going up towards Poitou, Charentes and Vendée, giving significant accumulations of rain. At the end of the morning, unstable rainstorms reached Corsica.

Monday afternoon
Rainstorms continue from central Aquitaine to Poitou to Vendée. Occasionally, expected rain intensities may exceed 10 to 15 mm/h. Surface runoff and mudslides may occur locally. Corsica is also affected by heavy stormy rains.

From Monday evening, with the rise of the depression towards the south of Brittany, the strongest rain-storm activity goes back towards the north of France, from Brittany to Hauts-de-France. Furthermore, heavy stormy rains come up from Corsica and reach the Alpes-Maritimes then the entire Alpine chain and during the night from Monday to Tuesday Franche-Comté as well as the Grand Est. In Alsace and Lorraine, the occurrence of these heavy rains on soils saturated with humidity could lead to the risk of flooding.

List of departments concerned