The storms expected on Saturday will be accompanied by “intense electrical activity”, “powerful gusts of wind”, “hail” and “heavy rainfall in a short space of time”

Initially, the “vigilance orange” for thunderstorms concerned up to 34 départements, but it now only applies to 28 départements for Saturday, when a major storm will cross a large part of the country, according to Météo-France.

From the end of the night, violent thunderstorms will affect an area stretching from the Landes to Poitou, accompanied mainly by heavy rain and locally by hail.

The departments affected are : Cher, Nièvre, Yonne, Côte-d’Or, Jura, Saône-et-Loire, Doubs, Territoire de Belfort, Haute-Marne, Aube, Haute-Saône, Ardennes, Marne, Meuse, Bas-Rhin, Haut-Rhin, Moselle, Vosges, Meurthe-et-Moselle, Allier, Ain, Cantal, Lot, Aveyron, Tarn, Puy-de-Dôme, Loire and Rhône.

A “major rainstorm” will cross “most of the country” on Saturday, says Météo-France in its latest forecast bulletin. “Only the regions stretching from Brittany to Nord-Pas-de-Calais, as well as Corsica, will remain unaffected by these storms, and will continue to experience calmer but cloudy weather”, it adds.

On Saturday afternoon and evening, “a wave of thunderstorms will move from the south-west to the north-east of the country”, warns Météo-France on its website in its orange “thunderstorms” alert. For the departments concerned, the weather service warns of a “severe summer thunderstorm situation requiring particular vigilance due to the geographical extent and intensity of the phenomena forecast”.

“In addition to intense electrical activity, these storms may cause violent gusts of wind, hail and heavy rainfall in a short space of time”, warns Météo-France.

Some regions spared

Only the regions stretching from Brittany to Nord-Pas-de-Calais, as well as Corsica, will remain unaffected by this bad weather, with calmer but cloudy conditions. A fairly strong south-easterly wind will blow until early afternoon, from the Provence-Alpes-Côte d’Azur region to the Massif Central.

Morning temperatures will range from 8 to 13 degrees from Brittany to Belgium, 15 to 20 degrees elsewhere, and up to 21 to 22 degrees in Corsica. In the afternoon, it will be 18 to 23 degrees near the Channel and the Atlantic, 23 to 28 degrees in the other regions, but up to 27 to 32 degrees from the Grand-Est to Berry, in Rhône-Alpes and Provence-Alpes-Côte d’Azur, and in Corsica, reaching 34 degrees locally on the Alsace plain and on the Ile de Beauté.

Sunday will bring a “return to calmer weather, but cooler for the season”, with “thundery residues” in the morning “from the Grand-Est to Limousin and Auvergne-Rhône-Alpes”, as well as a “persistent risk of thunderstorms in Rhône-Alpes” in the afternoon, says Météo-France in its latest forecast bulletin.