19 departments in the northern half of France on orange vigilance

The episode promises to be intense, even violent. The storms and heavy rains which will affect part of the northern half of France this Wednesday, May 1, have pushed Météo France to place 19 departments on orange alert for the risk of thunderstorms, floods or rain-flooding.

These are Yonne, Aube, Marne, Seine-et-Marne, Aisne, Oise, Paris, Seine-Saint-Denis, Val- de-Marne, Somme, Yvelines, Essonne, Eure-et-Loir, Hauts-de-Seine, Val-d’Oise, Eure, Calvados, Orne and Seine-Maritime.

In detail, Eure-et-Loir, Eure, Seine-Maritime, Calvados and Orne are on orange alert for the “rain-flood” risk, Calvados also being on orange alert for a risk of floods on the Orne. All other departments are on orange alert for the risk of thunderstorms.

Precipitation, hail and tornado risk

“A stormy wave, organized and intense, will sweep the regions from northern Burgundy to Hauts-de-France between the end of the afternoon and the second part of the night from Wednesday to Thursday”explains Météo France, in its latest vigilance bulletin.

The area where these powerful storms will erupt is largely visible on the map below. Designed with forecasts from the European model, it shows the average number of impacts per hour and per km2 during the evening of this Wednesday. Note, however, that the Burgundy-Franche-Comté and Île-de-France regions, which will be affected at the end of the afternoon, do not appear on the map, although thunderstorms will also be notable there.

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As a whole, the phenomenon promises to be ” very violent “according to Yann Amice, meteorologist for Weather & Co. “We are expecting very heavy rainfall, hail, squalls” with a high risk of tornadoes and very significant electrical activity, he explains.

Heavy rains in Normandy

Furthermore, significant amounts of rain should also be recorded in Normandy, which explains the passage of several departments in the region to orange “rain-flood” vigilance, or even to flood vigilance for Calvados.

These heavy rains are particularly visible in the animation below. Produced with forecasts from the French Arome model (the most precise of the models designed by Météo France), it shows the rain to be expected in France between the end of the afternoon of this Wednesday 1^er May and the early morning of Thursday 2.

The animation also shows that a very large part of the country will remain under the influence of rains which, although sustained and continuous, do not in themselves constitute a dangerous phenomenon.