The violent storms that will hit France in the coming hours have prompted Météo France to place 25 departments on orange alert for Saturday on Friday, June 28.
The storms justifying this increase in the alert level will first hit the southwest of France, late Friday night into Saturday. They will then move towards the Centre-Val de Loire and the Paris region. Then, during the day on Saturday, potentially very violent storms will break out in a large northeastern quarter of the country, from the Ardennes to the Lyon region, via Alsace.
Storms linked to a cold drop
These storms are due to the arrival in France of a cold drop (pocket of cold air at altitude) which, by hitting the mass of warm air which is currently flooding France, will cause instability there.
“We will have all the ingredients: very strong electrical activity, hail, possible tornadoes and sometimes gusts of wind at more than 100 km/h,” explains Yann Amice, meteorologist at Weather & Co.
Heavy rain is also expected as these storms pass. This is particularly what the animation below shows. Produced with forecasts from the French Arome model (the most precise of the French models), it presents the intensity of hourly accumulations to be expected in France during the day on Saturday.
Ultimately, over the entire episode, accumulations of more than 30 mm are expected locally, particularly in New Aquitaine, in central France and in Alsace.
Towards a calmer and cooler start to the week
This intense rain-storm degradation should gradually evacuate towards Germany, even if thunderstorms may continue to break out in certain areas of the northeast on Sunday morning.
“On Monday, the weather should return to calmer conditions,” continues Météo France in its forecast bulletin for dangerous phenomena. The weather at the start of next week will also be marked by a certain cooling.
