Weather Alert: Episode of snow and ice until Thursday

From Wednesday January 17 at 6:00 p.m. to Thursday January 18 at 12:00 p.m.

Situation

France finds itself in the middle of an air mass conflict this midweek. A depression, named Irene, rises from the Bay of Biscay then crosses the north of the country until Thursday. In contact with the cold air which resists in the north of the country, snowfalls occur between Hauts-de-France, Normandy, the Ardennes and the Paris region this night. On Thursday, the episode of winter weather progresses towards Burgundy and the north of Auvergne-Rhône-Alpes. From Thursday afternoon, with the sudden cooling, snow will appear, falling at lower and lower altitudes, reaching the plains in the evening, which is why this special release is extended to these regions.

Observation

This Wednesday

At 21h, it continues to snow in Hauts-de-France. The layer reaches 6 cm in Lille, 4 cm in Abbeville and Arras, 2 cm in Amiens. It is between Lille and Valenciennes that the snow depths are the highest, approaching 10 to 15 cm this evening. In Normandy, snow now replaces rain between Calvados, Eure and Seine-Maritime. The layer reaches 2 cm in Yvetot.

At 18 o’clock, snow covers the ground in Nord-Pas-de-Calais. The heights vary from 2 cm in Valenciennes, 3 cm in Arras to 5 cm in Lille. The freezing rains in the afternoon on the Seine-Maritime gradually give way to snowfall in the Pays de Caux.

At 15h, in Hauts-de-France, snowfall persists. They continue to intensify all the more easily as temperatures remain negative with -1°C in Lille where the layer reaches 3 cm on the ground. We measure 2 cm in Arras and Béthune. In Upper Normandy, freezing rain is replacing this morning’s snow. These freezing rains are temporary. It is snowing in the Pays de Bray and this snow will quickly reach the whole of Seine-Maritime. From Vexin to the Ardennes, in the north of Alsace, the freezing rains have stopped under slightly rising temperatures.

At 12, snowfall is increasing in Hauts-de-France, between the Somme and Nord-pas-de-Calais. This snow sticks to the ground due to the negative temperatures between Arras and Lille to the North Sea coast. Between Rouen and the north of Paris to Champagne, the Ardennes, the north of Lorraine and Alsace, the freezing rains continue.

At 9 o’clock, the disturbance invaded the entire north of the country. Despite the mild weather at altitude, rain affects the regions north of the Seine. This precipitation falling on frozen ground at temperatures between -2 and 0°C causes icy conditions between the Alsace plain, Lorraine, Champagne, the Ardennes, Normandy and the north of the Paris region.
Further north, only snow falls in Hauts-de-France, between the north of the Somme and Nord-Pas-de-Calais, which immediately sticks to the ground.

At 6 a.m., the rains from the disturbance extend from the Alps to Alsace to the Channel coasts to Brittany. Due to negative temperatures between Lorraine and Hauts-de-France, icy conditions are widespread. In the Paris region, it is raining with slightly positive temperatures in Paris and its suburbs. On the other hand, from the first heights and on the hills and plateaus of the Ile-de-France region, icy conditions are widespread. From Upper Normandy to North Picardy, snow falls with moderate intensities in the north of these regions. It is a heavy, sticky snow that immediately sticks to the ground.

Evolution

This evening
The situation is becoming complicated with snow which continues to progress towards the south and intensifies between Upper Normandy, Picardy and the Ardennes. It holds to the ground giving 2-3 centimeters per hour. The snow weakens in Nord-Pas-de-Calais and ends up evacuating from the south. On the other hand, the snow is gaining ground towards Lower Normandy, Ile-de-France and the north of Champagne where the soils begin to whiten at the end of the evening.

During the night from Wednesday to Thursday
It snows from Normandy to the Grand Est via Picardy and Ile-de-France. Snowfall is moderate with average intensities of 1 to 2 cm per hour and locally up to 3 cm/hour from the Ardennes to the north of Lorraine.

Thursday morning
The disruption will evacuate Normandy, Ile-de-France and Picardy, but with snow-covered roads, traffic conditions will be complicated on secondary road networks and untreated axes. The disruption will remain quite active in the Grand Est region with traffic conditions which could be delicate on secondary networks.

Thursday afternoon
The disturbance will slide south and give snow in the plains, from Berry to Bourgogne-Franche-Comté, to the north of Auvergne-Rhône-Alpes. The quantities will be less than in the northern regions and the snow will mainly hold on the lower heights.

For the snow episode on Wednesday, we expect:

– 1 to 5 cm in the far north, the Normandy coasts and the north of Île-de-France
– 5-10 cm in the interior of Lower Normandy, up to the hills of Artois
– 10-15 cm, locally 20 cm from the interior of Upper Normandy to the Ardennes

List of departments concerned