Nine departments are on orange alert for severe weather, national forecaster Météo-France has warned.
In the northeast, the Meuse and the Marne are on flood alert, while in the south, the Gard and Hérault are also on alert for flash floods, following overnight thunderstorms, which have moved east and are now threatening the Var, Bouches-du-Rhône and Alpes-Maritimes.
Sometimes referred to as 'épisodes cévenol' due to their regularity in the mountainous Cévennes, these autumn and winter storms can bring several months worth of rain in a matter of hours and cause dangerous flash flooding.
Anyone in areas likely to be affected by the storms - caused when mild, unstable air rising from the warm sea meets cold air from the land - to stay indoors (upstairs if possible), check on vulnerable neighbours, avoid waterways that can quickly become flooded, and keep informed by listening to local radio stations.
The Savoie and Hautes-Alpes remain on orange alert for avalanches, warning that the level of avalanche activity over the next 30 hours has been 'rarely observed'. The risk, it says, mainly concerns "the upper Maurienne, the south of the upper Tarentaise and eastern Queyras.
Meanwhile, several roads are closed to traffic in Paris as the Seine reached 3.86m. All departments in the Ile-de-France region have been on flood yellow alert since last week.
Searches are continuing for a police diver in Paris, who disappeared during an exercise on the Seine on Friday, and a 70-year-old German woman who is feared dead after the Aube flooded in the Haute-Marne a day earlier.
The death toll from Storm Eleanor stands at six.
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