A significant snow episode is affecting France this week. Many departments are affected, orange vigilance has been announced by Météo France.
The cold returns to France this week and snow is expected to fall this Thursday in several regions in the north of the country. In a bulletin published this Wednesday, November 20, Météo-France announced the placement on orange vigilance of 28 departments due to a risk of snowfall and the formation of ice.
The departments concerned are as follows: Côtes d’Armor, Île-et-Villaine, Calvados, Eure, Manche, Orne, Mayenne, Sarthe, Eure-et-Loir, Loir-et-Cher and the Loiret. To these are added those which make up Ile-de-France, but also Aube, Yonne, Haute-Marne, Côte-d’Or, Vosges, Haute-Saône, the Doubs, the Territoire de Belfort and the Haut-Rhin.
According to information from The Weather Channelsnowfall extends this Thursday from inland Brittany to the south of Normandy, towards Maine, Beauce, the Central region, the south of the Paris basin, to slide during the afternoon towards the center east, on the edge of Franche-Comté and southern Alsace. On the Île de France side, nothing is certain, even if a few snowflakes should be seen.
From this Wednesday, a clear cooling of temperatures was felt due to the formation of an air mass close to -35°C at 5000 m altitude according to Keraunosthe observatory for tornadoes and violent thunderstorms. This degradation is due to a new oceanic disturbance, leading to the collision of soft, humic air with the cold air already in place.
The Weather Channel explains that a very hollow depression named Caetano arrives in the morning this Thursday over Brittany and crosses France from west to east. The institute even gives details by region: “The depression is associated with a significant conflict between mild Atlantic air and much colder air present in the north of France. In contact with these two masses of air, precipitation is intense and occurs in the form of snow from northern Brittany and Normandy to Burgundy-Franche-Comté, via Center-Val de Loire, Ile-de-France and the south of the Grand Est region”, explains the specialized media.
And the snow therefore appears, it is a white coat which forms over a large territory: “Due to the intensity of the precipitation and the temperatures between 0 and 2°C, the snow easily sticks to the ground on the plains and plateaus from 150 m altitude with 3 to 8 cm and locally 10 cm above 300 meters The hold is more difficult in valleys and highly urbanized areas with 1 to 3 cm. This snow will often be accompanied by gusts of wind. and traffic conditions could be difficult, particularly on the secondary network,” indicates La Chaîne Météo.
Despite everything, the situation remains complex to predict for the end of the week: even if the numerical models were able to anticipate the risk of a “rain-snow” episode for the day of Thursday, it is difficult to determine the precise trajectory of this depression straight from the Atlantic. This is why the numerical models cannot state with certainty that snowflakes will fall in the regions located at the extreme of this phenomenon, which is the case for Île-de-France.
22:16 – Around fifty departments on orange alert Thursday for snow or wind
In detail, Météo-France announced in its 4 p.m. bulletin, which saw no change during the evening, that 49 departments were placed on orange alert either for snow or for wind tomorrow. To find out if you are affected, find the Météo-France vigilance map below without further delay. Note that with the exception of Hautes-Alpes and Alpes-de-Haute-Provence, which are on orange snow-ice alert, the southernmost departments are on alert for wind, while those to the north are on alert for snow-ice. The Loire-Atlantique and the Allier, both on wind alert, separate the two groups.
20:09 – What does the activation of the snow and ice plan mean in Île-de-France?
With snow and ice expected this Thursday in Île-de-France, from 11 a.m. to 8 p.m., the Paris police headquarters announced this Wednesday the move to level two, from 11 a.m. Thursday, of the snow-icy plan. This means that from this time, all vehicles driving will have to respect a general reduction of 20km/h in the speed limit. So, if the signs indicate 50km/h, you will have to drive at 30km/h, but also 60km/h instead of 80km/h or even 90km/h instead of 110km/h. Furthermore, vehicles weighing more than 7.5 tonnes will be prohibited from carrying out an overtaking maneuver on the main roads of Île-de-France.
????❄ The whole of Île-de-France is placed on orange snow/ice alert from tomorrow. Snowfall is expected to be 1 to 3cm and may make driving conditions difficult.
Find more information in the press release ???? pic.twitter.com/8faPmdNDdS
— Police Prefecture (@prefpolice) November 20, 2024
18:11 – How long will this winter episode last?
If Thursday promises to be particularly cool, in its bulletin, Météo-France announces “exceptional mildness” for Sunday, with “maximums that can approach 20°C in the north, [et même] 25°C in the Basque Country.
5:15 p.m. – Snowfall expected at midday in Île-de-France
Météo-France has placed Île-de-France on orange snow-ice alert from 11 a.m. this Thursday. Eight departments are concerned: Paris (75), Seine-et-Marne (77), Yvelines (78), Essonne (91), Hauts-de-Seine (92), Seine-Saint-Denis ( 93), Val-de-Marne (94) and Val-d’Oise (95). These snowfalls will begin in the west of the region: “The intensities are low, the precipitation intermittent in the north and more continuous towards the south of the region”, specifies the official meteorology and climatology service. In France. Even if the hold of the snow on the ground remains “uncertain” given the still warm ground, icy conditions are expected overnight from Thursday to Friday. Météo-France still anticipates difficult traffic conditions due to the 1 to 3 cm of snow on the ground forecast locally and the 4 to 7 cm expected in the south of the region (south of Yvelines and south of Essonne). The Weather Channel recommends staying at home until Friday if you can not travel.
16:13 – Up to 5 or 10 cm of snow in Brittany
Rennes, Brest, Saint-Brieuc… These cities are all affected by the snowstorm which is expected on Thursday. From dawn, a white coat will cover the north of Brittany. To the south, violent winds reaching 120 km/h will be present on the coasts of Morbihan. For Steven Tual, meteorologist and creator of “Temps Breton”, there is no doubt about this spectacular climatic episode: “Snow? Thursday, it is now 100% certain”. Several departments in the region have already been placed under orange vigilance by Météo-France. Indeed, over a large part of central Brittany and the east of the region, 2 to 5 cm of snow are expected: “The snowy area will begin at the border of the Monts d’Arrée and will extend to Rennes ” he explains to France 3 Régions. But the majority of falls should fall on Fougères and there, we could reach “10 cm of snow on the ground”, specifies the meteorologist.